Processing Order
Incoming mail addressed to a valid local address is processed in the following order.
- SMTP Access Control. The SMTPD process checks to see if the connecting IP is listed in the Access Control dialog box. If it is listed in deny access list, the connection is denied. If it is listed in the grant access list, the connection is allowed and processing continues as described in the next step.
- Verification Tests. If you have the anti-spam verification tests enabled, they are performed to verify the "Mail FROM" address, the HELO/EHLO domain, and perform a reverse DNS lookup. If a message passes all the checks, connection filtering is performed.
- Connection Filtering. If you have connection filtering enabled it compares messages against configured DNS black lists. If the message does not match a black list, IMail Anti-Virus scans it.
- IMail Anti Virus. If you have IMail Anti-Virus installed, it checks the message for infected files or code. If infected, the mail is repaired, bounced, redirected, or deleted, according to the settings on the Anti Virus tab. If the file is not infected, content filtering attempts to identify whether the message is spam.
- Content Filtering. If you have content filtering enabled, it determines if the message is likely to be spam. If the message is determined to be spam, it is either deleted, sent to the specified address, or an X-Header is inserted. If the message is not spam, aliases are checked.
- Alias. IMail Server checks to see if the addressee matches an alias in the destination domain. An alias is considered to be one of the following: standard alias, group alias, program alias, pager alias, beeper alias, fax alias, or a list-server mailing list name.
- If there is a match to a program, beeper, pager, or fax alias, IMail Server executes the program or activates the beeper, pager, or fax.
- If there is a match to a standard or group alias, IMail Server resolves the alias to the appropriate user ID(s), and checks the user ID.
- If there is a match to a list-server mailing list, IMail Server processes the mail according to the settings for that list.
- If there is no match to any alias, IMail Server checks the user ID as described in the next step.
- User ID. IMail Server determines if the user ID is valid for the destination domain. If invalid, the mail is returned to the sender. If valid, delivery rules are checked.
- Delivery rules for a list-server mailing list. If the message matches the rule criteria for the list, delivery follows according to that rule. If not, then the message is sent to the list server. If the message is not addressed to a list, Forwarding is checked.
- Forwarding. IMail Server determines whether an address is present in the Forward box on the General tab for the account. If so, IMail Server forwards the mail. If not, the mail is delivered to the user ID according to the established delivery rules.
- Delivery rules for the mail host. IMail Server determines if the message matches a rule for the mail host. If so, delivery follows according to that rule. If not, then rules for the user ID are checked.
- Delivery rules for the user ID. IMail Server determines if the message matches rule criteria for the user ID. If the message matches rule criteria for a user ID, then delivery follows according to that rule. If not, then the Info Manager is checked.
- Info Manager. IMail Server determines whether the user ID has the Info Manager enabled. If so, the automatic response is sent and the message is delivered to either the forwarding address or (if no forwarding address) to the sub-area or mailbox specified. If the Info Manager is not enabled for this user ID, the vacation setting is checked as described in the next step.
- Vacation. IMail Server determines whether the user ID has a vacation message enabled. If so, the vacation message is sent. If not, the message is delivered to the User ID.
| Note: If you have configured the anti-spam features, see "Processing Order" for information on anti-spam processing. |
