Sambar Server Documentation

Mail Frequently Asked Questions


How do I send attachments larger than 100K via WebMail ?
How can I block attachments with executable or Visual Basic code ?
How do I setup two domains in my mail server ?
Netscape messenger does not allow @ in the username, how can a virtual-hosted client access mail ?
Why do ISPs block port 25 (outgoing SMTP mail) ?
When should I use the Relay Domains mail configuration parameter ?
I see lots of "can't connect to hotmail.com" in the router.log. Why can't I send outgoing mail ?
Why can't JavaMail clients seem to send to my server ?
How can I change the character set WebMail uses when sending mail ?
Why can't I retrieve .doc and .xls file attachments in WebMail when SSL is used ?

How do I send attachments larger than 100K via WebMail ?
There are two settings that determine the size of a mail message. The first Mail Message Size in the config/mail.ini file is used by the SMTP server to restrict the size of any single mail message received by the server. By default, mail messages are restricted to 200K bytes of data (including attachments).

The second, less obvious, setting is the Maximum Content-Length in the config/config.ini file. This setting indicates the maximum size of any HTTP POST content received by the server. Since WebMail goes through the web server when sending messages to the SMTP server, this value must reflect the maximum message size you wish to send.

How can I block attachments with executable or Visual Basic code ?
Some attachments can be stopped using the existing filtering mechanisms by adding rules such as:

delete "" CASEI body "filename=\"*.exe\"*
delete "" CASEI body "filename=\"*.vbs\"*

There is one limitation to the above filtering rules, which is that the body filtering rules only apply to the first 2K bytes of the body. So if the attachment appears after a long textual message (or is the second attachment), the above filtering rules will not apply.

How do I setup two domains in my mail server ?
Modify the Local Domains in the [smtpd] section of the config/mail.ini file to have the domains you wish to support:

Local Domains = *domain1.com *domain2.com *domain3.com
Then when creating users, you have the option of creating the user account as:
tod@domain1.com
tod@domain2.com
tod@domain3.com
Each of the above map to a separate user account. If, however, you have only a single account tod, then mail directed to any of the domains will go into that single account.

Netscape messenger does not allow @ in the username, how can a virtual-hosted client access mail ?
To get around this limitation in the Netscape client, the star (*) symbol can be used in place of the at (@) symbol. The POP3 and SMTP servers will translate a star (*) to the at (@) symbol during user login.

Why do ISPs block port 25 (outgoing mail) ?
Many ISPs (Internet Service Providers) are blocking what is called "Port 25" which is the port used to send e-mail. They do this in an attempt to reduce the amount of "SPAM" mail that is sent. All e-mail sent via the Internet is routed through port 25, the channel used for communication between a mail client and a mail server.

Regretably, there is nothing that can to route around port 25 blocking. The only option is to setup your SMTP server to "relay" outgoing mail via your ISPs SMTP server or select an alternative ISP.

When should I use the Relay Domains mail configuration parameter ?
Almost never! This is an often mis-used parameter. It should only be used when your mail server is designed to act as a "relay" for one or more other servers.

I see lots of "can't connect to hotmail.com" in the router.log. Why can't I send outgoing mail ?
This is very likely a problem resolving the mail domain to a mail server. The Mail Server uses the DNS Primary and DNS Secondary entries in the config/config.ini to resolve mail server addresses. If these DNS servers are unavailable or there is no corresponding a mail server name, the server attempts to connect to the host identified by the mail address. For sites such as hotmail.com, this is always wrong. The server should be attempting to connect to something like: mail.hotmail.com or smtp.hotmail.com. If you see it attempting to connect to just hotmail.com, this means there is no corresponding MX record entry.

Why can't JavaMail clients seem to send to my server ?
Some versions of the JavaMail SMTP transport do not support multi-line 220 response headers. The Sambar SMTP server, by default, sends a multi-line SMTP EHLO message with a "No UCE" message. By removing the SMTP_WELCOME macro defined in config/macros.ini, the server will send a single line 220 welcome message and older JavaMail applications will succeed.

How can I change the character set WebMail uses when sending mail ?
By default, the WebMail interface sends all mail with the ISO-8859-1 character set. To change the character set, modify the /sysuser/webmail/sendmail.stm file to pass the optional "charset" parameter.

Why can't I retrieve .doc and .xls file attachments in WebMail when SSL is used ?
Due to some quirks in the Microsoft Office platform, .doc, .xls and other Microsoft Office (associated) applications appear to be unable to connect via SSL to retrieve the contents of the attachment. The only solution when using WebMail in conjunction with SSL is to right-click the attachment link and save the attachment to disk; then you will be able to open it from your local drive.

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