What is ISMail Pro?
ISMail Pro is a mail server for Windows PCs. It supports ESMTP, POP3, IMAP4, Webmail on multiple domains with anti-spam, backup, relay, remote administration, and other features.
ISMail Pro is an enhanced version of the ISMail product (comparison)
Does ISMail Pro have Webmail?
Yes, if used with the ISMail-Web plug-in. For more information, see the ISMail Pro-Web FAQ.
What does ISMail Pro cost?
See price list.
What operating system does ISMail Pro require?
ISMail Pro requires either Microsoft® Windows® 98, 98SE, NT4.0 (with SP3), 2000, XP, or 2003.
What is the minimum system configuration?
Minimum recommended configuration for 100 users is:
CPU: P3 400Mhz
RAM: 128MB
Disk: 10GB
A larger hard disk is recommended if mail accounts do not have any quotas.
Do I need a static (fixed) IP address to use ISMail Pro?
No, but a static IP address is highly recommended and is a de facto requirement if ISMail Pro is used on the internet.
Can I run ISMail Pro with a cable modem?
So long as you have access to port 25 (SMTP) and either port 110 (POP3) or port 143 (IMAP4), you can run ISMail Pro. Also, check with your cable modem service to find out their policy regarding servers.
Will ISMail Pro run with a Firewall, Router, or Proxy Server?
Yes. Please see the section on Firewalls, Routers, and Proxy Servers.
How do I install or uninstall ISMail Pro?
Please see the ISMail Installation Guide for detailed instructions.
What can I do with the Trial copy of ISMail Pro?
The trial copy is a full copy of ISMail Pro and includes all features and options.
The trial copy will, however, display a License Manager window whenever it is started, and will expire after a limited period of time. Click 'OK' in the License Manager window to run the trial version of ISMail Pro.
How do I setup ISMail Pro?
How to Setup a Mail Server is a beginner's guide to the setup and use of a mail server.
ISMail Pro setup instructions are also available in the ISMail Pro User Guide (on-line or within the product). Some of the individual setup options are also discussed in this FAQ.
Once ISMail is setup, run the ISMail Setup Test (a.k.a. Basic Access Test) to check that ISMail Pro is working, the mail servers are accessible from the internet, and the DNS settings are correct for the domain(s).
What is the primary domain name used for and how do I set it up?
The primary domain name is used to identify the mail server domain to others wishing to send you email. It must be a registered internet domain (or subdomain) name and correctly configured in a DNS.
Since the domain name is used for addressing email messages, the actual domain name should be used, and not an alias:
See the ISMail Pro User Guide setup instructions for further information.
How do I setup multiple domains?
Multiple domains may be setup using the 'Multiple Domains' configuration page. To setup multiple domains using the same IP address, use the Address Mapping 'virtual' rather than specifying an IP address.
What is the DNS used for and how do I set it up?
The DNS is used to lookup the IP address for a domain to which you want to send a message.
Etner the IP addresses for your ISP DNS servers here.
The default values (or 'Don't Know DNS Servers' button) will set the DNS servers to the internet root servers. This setting may be temporarily used, but is NOT recommended as it may not correctly resolve all domain names.
Note: the DNS nameservers used for sending a message to others are different than the DNS nameservers used by others to send a message to your domain(s). This setting is only used for sending a message to others; the DNS settings for your domain(s) specifiy the nameservers used by others to send a message to your domain(s).
What are the user accounts and how do I set them up?
User accounts are the mail accounts supported by ISMail Pro, from which you send and receive mail messages.
Note: the special account 'nobody' can be created to accept any messages that arrive for unknown users; otherwise, these messages are bounced.
See the ISMail Pro User Guide for further information.
How do I setup an Outlook or Outlook Express account?
See Outlook or Outlook Express Account Setup
I have multiple domains but can not receive mail on some of them. How do I fix this?
When using more than one domain, the email client program must specifiy both the account name and the domain name for the 'incoming' mail server login so that ISMail Pro knows which domain to use.
For example, if there is an account 'user1' on 'domain1.com' and another account with the same name ('user1') on 'domain2.com', then the email client (e.g. Outlook) must be configured with the first account as 'user1@domain1.com' and the second account as 'user1@domain2.com'. These values are set in the login information (account name) for the 'incoming' mail server.
Note: Webmail automatically appends the domain name so you need not do so in the Webmail login.
I setup two user accounts with the same name on two different domains, but when I login I always get the same account. How do I fix this?
See previous item.
See the ISMail Pro User Guide for further information.
How can I setup a 'catchall' account that will receive messages addressed to all unknown users on a domain?
To receive messages addressed to unknown users on a domain, add a user account named 'nobody' to the domain. Otherwise, messages addressed to unknwn users on a domain will be refused from the sender. If you have more than one domain and want 'catchall' accounts on any other domain, add an account named 'nobody' to each domain where the 'catchall' account is desired.
What are mailing list accounts?
Mailing list accounts are mail accounts used to distribute messages to a list of 'subscribers', which are just other email accounts. A copy of each message sent to a mailing list account is automatically forwarded to each of the subscribers.
How do I add a mailing list account?
On the ISMail Pro 'Accounts' configuration page:
How do I add a 'subscriber' a mailing list account?
On the ISMail Pro 'Accounts' configuraiton page:
How do I get ISMail Pro to work behind a firewall, router, or proxy server?
A firewall, router, or proxy server is designed to be located between a user's machine and the internet. It will hide the IP address of the user's machine from view, thereby preventing direct access by external users or programs, some of whom may be malicious. ISMail Pro operates on a very restricted set of ports and contains a number of security safeguards. It can be exposed for access to the SMTP (port 25), POP3 (port 110), and IMAP4 (port 143) protocols. Most firewalls, routers, and proxy servers can be configured to enable external access to these ports for one or more machines which they protect. Check the vendor's user manual for instructions on how to do this. Typically, it can be done using a telnet program or web browser. Also, run the ISMail Setup Test for more information.
Firewalls may also be setup using software on the server machine. See, e.g., Windows Firewall Setup.
How does ISMail Pro protect against spam?
ISMail Pro has 6 layers of defense against spam at the connection, protocol, and message levels:
The blocked IP list is used to deny a connection from any specified IP, or range of IP addresses.
DNS RBL (real-time blackhole) filters are used to deny access from any IP appearing in an internet DNS RBL database. RBL databases generally contain IP addresses of known sources of spam or other messages deemed undesirable. Many DNS RBL databases are available (some free, some commercial); an example using a free DNS RBL is given below.
Reverse DNS checking is used to verify that the sender's IP address has a reverse DNS (PTR) record. The value of the reverse DNS record is not checked (frequently, the record just identifies an ISP), but the record must exist. Legitimate senders nearly always have reverse DNS records; missing reverse DNS records make it harder to identify a sender.
Blacklists (Whitelists) are used to deny (accept) access from specific IP addresses, domains, or email accounts. These values are checked at the SMTP protocol level and not in individual message headers. Although these values can be forged, it it somewhat harder to forge them at the SMTP protocol level than in the message headers.
The Greylist is used to require that messages from unlisted IP/sender/receiver 'triples' be retried before being accepted (listed). This reduces 'hit and run' spam attacks and provides time for offending IP addresses to appear in DNS RBLs, where they will be found using the DNS RBL filters. More information on Greylisting can be found at: http://projects.puremagic.com/greylisting/
Content filters are used to mark or delete messages based on identifiable message header or content information.
What is the easiest way to setup ISMail to block spam?
The easiest way to block spam is to:
How do I setup ISMail Pro to block specific IP addresses?
On the ISMail Pro Access configuration page:
How do I setup ISMail Pro to use DNS RBL filters (e.g. Spamhaus)?
On the ISMail Pro Access configuration page (screenshot):
Note: the Spamhaus project is at http:/www.spamhaus.org and describes a test which can be run to verify that the DNS RBL filter is working.
How do I setup ISMail Pro to use Reverse DNS checking?
On the ISMail Pro Access configuration page (screenshot):
How do I setup ISMail Pro to use Blacklists and Whitelists?
Blacklists and Whitelists can be setup at the server, domain, or user account level. Server-level blacklists and whitelists affect all messages; domain-level and user account-level blacklists and whitelists only affect messages to or from specific domains or user accounts, respectively.
Blacklists and whitelists may contain IP addresses, domain names, or account names.
To add or remove a server-level blacklist or whitelist entry:
To add or remove a domain-level blacklist or whitelist entry:
To add or remove a user account-level blacklist or whitelist entry:
How do I setup ISMail Pro to use Greylisting?
On the ISMail Pro Access configuration page:
To change the Greylist options:
How do I setup ISMail Pro to use Content Filters?
To use Content Filters for all ISMail Pro domains or for a specific ISMail domain:
Note: the Content Filters are quite aggressive and will filter messages that do not use strict MIME format. Due to the large number of mailers which fail to conform to MIME, Content Filters may result in significant false positives and should be used only when senders are known to conform to MIME.
How do I tag messages identified as spam for email client filtering?
To tag messages matched by a Content Filter so they can be later filtered by an email client program or email client filter:
Then, in the email client program (or email client filter), search for '[SPAM]' in the 'Subject' line of messages. If '[SPAM]' is present, then the message was matched by the Content Filter.
How do I get ISMail Pro to work with anti-virus software?
ISMail Pro can run any anti-virus scanner with a DOS command-line interface. The scanner will be run on each message sent or received. This provides protection from external virus infections, as well as stopping the spread of mail-borne viruses from internally infected machines.
Anti-virus setup instructions for many popular anti-virus scanners are listed below.
How do I setup and configure ISMail Pro to work with ClamAV?
To use ISMail Pro with ClamAV, download and install the ClamAV system and then configure ISMail Pro to use ClamAV as follows:
Primary Method (requires .NET, which may also be installed at this time):
1. Download and install ClamAV for Windows from:
http://w32.clamav.net
2. Update ClamAV virus definition files automatically using the 'freshclam.exe' utility. This can be done by running 'freshclam.exe' (e.g. c:\program files\clamAV\freshclam.exe) in the Windows scheduler on a daily basis.
Run 'freshclam.exe' manually to initialize the virus database (c:\Program Files\clamAV\freshclam.exe).
3. Setup ISMail Pro configuration for ClamAV:
4. Start ClamAV from a DOS command window using c:\Program Files\clamAV\clamd
Alternate Method (older method, does not require .NET):
1. Download and install ClamAV for Windows from:
http://www.sosdg.org/clamav-win32/index.php
2. Update ClamAV virus definition files automatically using the 'freshclam.exe' utility. This can be done by running 'freshclam.exe' (e.g. c:\clamav-devel\bin\freshclam.exe) in the Windows scheduler on a daily basis.
3. Setup ISMail Pro configuration for ClamAV:
4. Improving ClamAV Performance
For much faster anti-virus scanning, a background scan daemon 'clamd.exe' and file submission program 'clamdscan.exe' can be used instead of running the complete anti-virus scan utility 'clamscan.exe'.
To use clamd/clamdscan, ISMail Pro must be configured to use clamdscan.exe and the clamd.exe program must be started as follows:
To use clamdscan.exe with ISMail Pro:
To start clamd.exe:
Note: check the Task Manager to make sure clamd is running as it is sometimes necessary to run 'start-clamd' twice.
To stop clamd:
5. Finding problems with ClamAV
To find problems with ClamAV, the scanner can be setup to log results as follows:
The file 'c:\clamscan.log' will show the results of the virus scan.
How do I configure ISMail Pro on Windows NT/2000/XP to work with F-Prot Anti-VirusTM software (http://www.f-prot.com/)?
Next, on the ISMail Pro Anti-Virus configuration page:
Note: Testing the anti-virus scanner:
How do I configure ISMail Pro on Windows 98/ME to work with F-Prot Anti-VirusTM software (http://www.f-prot.com/)?
Next, on the ISMail Pro Anti-Virus configuration page:
Note: Testing the anti-virus scanner:
How do I configure ISMail Pro on Windows 98/ME/NT/2000/XP to work with Norton AntiVirusTM software (http://www.symantec.com)?
Next, on the ISMail Pro Anti-Virus configuration page:
Note: Testing the anti-virus scanner:
How do I configure ISMail Pro on Windows 98/ME/NT/2000/XP to work with Computer Associatess eTrust Antivirus 7 (http://www.ca.com)?
Next, on the ISMail Pro Anti-Virus configuration page:
How do I configure ISMail Pro on Windows 98/ME/NT/2000/XP to work with Eset NOD32 (http://www.nod32.com)?
Next, on the ISMail Pro Anti-Virus configuration page:
How do I setup message archival?
To setup archival for all incoming and outgoing messages:
Where are archived messages stored?
All archived messages are stored in special accounts named 'archive-' followed by the account name. For example, messages for account 'joe@domain.com' would be stored in the account 'archive-joe@domain.com'.
Archive accounts can be accessed using standard email clients.
How can I setup an account to automatically reply when a message is received?
An autoresponder can be setup for any account on the ISMail Pro configuration 'Accounts' page. Check the 'Autoresponder Message' box and enter the text of the message to send. If you also want to specify the 'Subject' line of the message, enter it into the 'Autoresponder Subject' box. Then, click 'Apply'.
What are relays?
Relays are backup (or 'secondary') mail servers for the main ('primary') mail server. Relays will accept messages for accounts on the primary mail server, and forward them to the primary mail server when it becomes available.
ISMail Pro may be used in relaying as a:
If ISMail Pro is the primary, another copy of ISMail Pro or a different mail server may be used as the secondary. The same applies if ISMail Pro is the secondary; another copy of ISMail Pro or a different mail server may be used as the primary.
How do I configure the main ('primary') ISMail Pro server to use a backup ('secondary') mail server?
On the main ('primary') ISMail Pro server:
How do I configure the backup ('secondary' ) ISMail Pro server to use the main ('primary') mail server?
On the backup ('secondary') ISMail Pro server:
(*)An MX record pointing to the host name of the backup ('secondary') mail server, and an A record defining the IP address of the host name of the backup ('secondary') mail server must be added to the DNS for the domain name. The priority of the MX record for the secondary should be lower (i.e. numerically higher) than the priority for the primary MX record.
How do I setup and access Remote Administration?
To use Remote Administration, install the ISMail Pro-Web plugin.
See the ISMail Pro-Web FAQ and ISMail Pro-Web User Guide for more information.
How secure is ISMail Pro?
The ISMail Pro default configuration does not allow open relaying, thus preventing a major source of spam. Senders must be authenticated to send messages to remote domains.
ISMail Pro does not accept messages unless the account name is valid or unless a special 'catch all' account is defined. This reduces 'bounce' traffic considerably.
ISMail Pro limits the number of connections to counter denial-of-service attacks.
ISMail Pro allows access to the server machine on ports 25 (SMTP), 110 (POP3), and 143 (IMAP4). Access is handled by these server programs.
While there are no known security holes in the latest versions of the servers, users should of course remain alert for mail message attachments containing worms, viruses, or other malicious objects which could be contained within messages.
I can not send any mail directly. What can I do?
ISMail Pro supports a 'Smarthost' feature, which allows ISMail Pro to use an ISP (or other) mail server to send messages. Because ISP mail servers are more 'trusted' than individual mail servers (e.g. they have static IPs, valid reverse DNS entries, etc.), all domains should accept their mail.
To setup a 'Smarthost':
I can send mail directly to some domains, but not to others. What can I do?
The ISMail Pro 'Smarthost' may be setup to be used only when sending a message directly fails. To to this, use the ISMail Pro configuration 'Connections' page: check the 'Smarthost' box and enter the name of the mail server to use (e.g. smtp.your-isp-mailserver.com). Make sure the 'Use Smarthost Exclusively' box is NOT checked. Then restart the ISMail Pro SMTP server.
I setup a Smarthost but it will not accept my mail. What can I do?
Some 'Smarthost' mail servers require authentication to send messages. ISMail Pro supports SASL CRAM-MD5 and LOGIN authentication with a 'Smarthost'. To setup a 'Smarthost' to use authentication, use the ISMail configuration 'Connections' page: check the 'Authenticate' box and enter the name and password for a valid mail account on the 'Smarthost' mail server (not an ISMail Pro account). Then, restart the ISMail Pro SMTP server.
Can I access ISMail Pro through a web-based mail client such as Mail2Web?
Yes. Although such web-based mail clients do not store messages, they may be used to access (read and send) mail through ISMail.
With Mail2Web, use 'Advanced Login' to login. Enter the server name and then the complete user and domain names, separated by a '%' (e.g. me%mydomain.com). Although this requires a little more typing, it will allow access to any account on either a single domain or a multiple-domain ISMail Pro system.
Selecting the 'IMAP4' mail protocol will usually be faster than 'POP3'.
Can I access ISMail Pro through a web-based mail system such as Yahoo!® Mail?
Yes. Such web-based mail systems frequently allow external mail accounts to be checked.
When adding an ISMail Pro mail account, enter the ISMail Pro domain name as the 'Server', then enter the complete user and domain names, separated by a '%' as the 'Username' (e.g. me%mydomain.com). Enter the password. Then Save the configuration settings.
Currently, only POP3 can be used to access ISMail Pro this way.
Does ISMail Pro have its own web-based mail?
Yes. ISMail Pro supports web-based mail ("Webmail") directly with the ISMail Pro-Web plugin. The plugin enables direct access to ISMail through a web browser without using any external web-based mail systems.
ISMail Pro is not working. What should I do?
If you are having trouble sending mail, see Troubleshooting (problems sending mail).
If you are having trouble receiving mail, see Troubleshooting (problems receiving mail).
If you are having trouble both sending and receiving mail, first see Troubleshooting (problems sending mail) and then see Troubleshooting (problems receiving mail).
If ISMail Pro is still not working, please contact Technical Support.
ISMail Pro displays a 'Missing .dll' message. What should I do?
ISMail Pro requires some network support that is not installed on all machines (e.g. modem files). Visit the Microsoft website and search for 'DLL Help Database' to find out which product or service pack you need.
An ISMail Pro SMTP, POP, or IMAP server will not start. What should I do?
If a mail server does not start, make sure that no other server of the same type is running. The following areas should be checked:
Depending on which server fails to start, it may be possible to open a DOS command window on the mail server machine and 'telnet' to the server port to check if another server is running. The DOS 'telnet' command lines for each server are:
If a 'greeting' message appears, then another server of the same type is running and must be stopped before starting ISMail.
An ISMail Pro SMTP, POP, or IMAP server will not start but no other server of the same type is running. What should I do?
A server may fail to start if the installation was corrupted. To check the installation, run the Registry editor ('regedit') and open the key:
HKEY_LOCAL_MACHINE/Software/InstantServers/ISMail
A subkey, numbered with the installed version of the system should be displayed. If more than one numbered subkey is displayed, the installation is corrupted. Either: A) delete the incorrect key and re-start the server, or B) uninstall ISMail Pro, delete the ISMail key, re-install ISMail Pro, and re-start the server.
If a mail server still does not start, check that the pathnames in the Registry entries refer to the actual installation directory of the program (default: c:/program files/instantservers/ismail).
If you can not send mail:
Troubleshooting: Receiving mail has additional troubleshooting information
Also, see the ISMail Pro User Guide 'Log' section.
If you can not receive mail:
A '451' error message is displayed when sending mail. What should I do?
A '451' error may occur if an email client does not authenticate with the mail server. Check that the email client:
See ISMail Pro User Guide 'Setup: Accounts: Client' for examples.
I am receiving a '452' error message when sending mail. What should I do?
Depending on the type of '452' error, different actions should be taken. If the '452' error indicates a 'temporary embargo' on the message, then resending it may resolve the problem. If the error still occurs, contact Technical Support.
Messages do not get sent to certain domains. Instead, '499' errors occur. What should I do?
Some mail servers require that any IP connecting to them have reverse DNS record. A reverse DNS record identifies the ISP responsible for that IP address. Request your ISP to add a reverse DNS record for your servers's IP address.
A '530 Authentication failed' message is displayed when sending mail. What should I do?
A '530' error may occur if an email client does not authenticate with the mail server. Check that the email client:
I am receiving a '550' bounce message when sending mail to accounts on certain domains. What should I do?
A bounce message can occur for several reasons, and depends on the domain bouncing the message. Some specific Problems and Solutions are given below. More information may be available if the error message contains a link to the web site of the organization responsible for the receiving mail server.
Problem: User account - unknown (or disabled)
Solution: Verify that the recipient account is valid and is working by sending a message to that account from another mail account which uses a different sending mail server.
Problem: Open mail server - sending mail server is on an 'open relay' or 'blackhole' list
Solution: Run a 'Database lookup' at http://ordb.org to see if your server (the sending server) is listed as a 'black hole' or 'open relay'. If so, follow the given instructions to have it removed. Be sure to check the 'non-ORDB RBLs' as well.
Problem: IP Address - the receiving server can not verify who 'owns' the sending server's IP address.
Solution: The receiving server may reply with an error about 'IP address subdelegation'. If so, then the sending server's IP address is part of a large block of IP addresses and does not indicate the actual owner. Contact your ISP to have your IP address(es) subdelegated, or use the ISMail Pro 'Smarthost' feature.
I am receiving a '55x' bounce message when sending mail to accounts on aol.com. What should I do?
See http://postmaster.info.aol.com/
As a workaround, the ISMail Pro 'SmartHost' feature can be used. A 'SmartHost' allows messages to be sent using another mail server instead of being sent directly.
I am receiving a '550' bounce message when sending mail to accounts on rr.com. What should I do?
There are several possible reasons for this. See http://security.rr.com/
Also see 'Problem: IP Address' above.
I see a 'Maximum line length overflow' message in the SMTP log files? What should I do?
Some email client programs violate the SMTP maximum data line length specification of 1024 bytes. To accept messages from these clients, add the following DWORD to the Registry (using 'regedit'):
HKEY_LOCAL_MACHINE/Software/InstantServers/ISMail-Smtp/SmtpReceiver//SmtpDataLineMax
That is, add a DWORD 'SmtpDataLineMax' into the Registry key specified before the '//' above.
The default value is 1024 characters, and virtually any reasonable length (e.g 1000000) may be used.
The SMTP server must be restarted for this change to take effect.
I am having problems starting (or stopping) the ISMail Pro SMTP server under WindowsNT. What should I do?
By default, older versions of ISMail Pro require the Windows DNS Client Service, which is not present on WindowsNT. The simplest solution is to upgrade to the latest version of ISMail Pro.
With older versions, the ISMail SMTP server can either be run as a Windows Application, or by editing the Registry, to run ISMail SMTP as a Windows Service.
To run ISMail SMTP as a WindowsNT Application:
To run ISMail SMTP as a WindowsNT Service: