WhiteLists are used to fight spam. It is a part of ArGoSoft Mail Server Pro, starting from version 1.8.6.0.

Each user of ArGoSoft Mail Server Pro can create a list of email addresses, from which an account will accept mail. Account will accept mail ONLY from these addresses, and will reject all other mail (unless Auto WhiteListing for account is enabled, see below).

WhiteLists can be set up individually by users, they are accessible from the web interface, by clicking WhiteList link on the message list page, or via the server console, from Tools - Configuration, select the user, click Properties - White Lists tab.

If WhiteLists are enabled, server checks whether address, transmitted with MAIL FROM SMTP command (which does not have to match FROM or REPLY-TO headers, contained in the email message) contained in the list, and if it does not, bounces mail to the sender. If Auto WhiteListing is enabled, then server places the message on hold, and sends to the MAIL FROM address a confirmation request, asking the sender to click certain link. After sender clicks the link, hold on all messages from that particular MAIL FROM address gets released, mail is moved to the user inbox, and an address is added to the WhiteList. It means, if more messages arrive from the same sender, they will go to the inbox directly, without placing on hold, and requesting.

Messages on hold will stay in the _Hold folder (which is accessible via Web interface, or IMAP the same way as you can access any other folder) for specified amount of time (by default, 24 hours), and are getting deleted afterwards. If confirmation does not arrive within 24 hours, sender will have to resend this mail again.

Currently, WhiteLists do not work with accounts, which are forwarded (even if Keep Copies option is on).

You should not use whitelists for accounts, which are receiving newsletters, or other kind of automated messages.

There is an important issue to consider: you may have problems with receiving or sending mail to someone, who uses similar service, not provided by our server (if another party uses our server, all will be fine, because our server is able to detect confirmation requests, generated by our server at another location):

Consider the following scenario:

• You (joe@joesdomain.com) are sending mail to jane@janesdomain.com who is also using WhiteListing (not provided by ArGoSoft Mail Server Pro)
• Your email arrives to janesdomain.com server, is placed on hold, and an automated confirmation request is sent back to you;
• Confirmation request comes to your server. Your server does not detect, that it is a confirmation request, and places it on hold; (note, that your server will not send the confirmation request on this last email, because email from that address already sits in the Hold folder, so, there will be no looping);

So, neither you, nor jane@janesdomain.com can see your confirmation requests, you cannot confirm your mail, and Jane cannot confirm hers. Mail is lost, unless, of course, you or Jane find it in the Hold folder before it expires and gets deleted).