# Processing Order

Incoming mail addressed to a valid local address is processed in the following order.

1. SMTP Access Control. The SMTPD process checks to see if the connecting IP is listed in the Access Control dialog box in IMail Administrator. If it is listed in the deny access list, the connection is denied. If it is listed in the grant access list, the connection is allowed and processing continues.

2. Verification Tests. The verification checks are performed to verify the "Mail FROM" address, verify the HELO/EHLO domain, and perform a reverse DNS lookup. If a message passes all the checks, Connection Filtering begins.

3. Connection Filtering. Connection filtering compares messages against the configured DNS black lists. If the message matches a list, it is processed according to the connection filtering settings. If the message does not match a black list, it is scanned by IMail Anti-Virus.

4. IMail Anti-Virus. If you have IMail Anti-Virus installed, it checks the message for infected files or code. If infected, the mail is either repaired, bounced, redirected, or deleted, according to the settings on the Anti Virus tab. If the file is not infected, or is repaired, the processing rules for a list server mailing list are checked.

5. Content Filtering. Content filtering is initiated to determine if the message is likely to be spam. If the message is determined to be spam, it is deleted, forwarded to a specified address, or delivered with an inserted X-Header. If the message is not spam, it is passed on to the IMail delivery rules.

6. Alias. IMail Server checks to see if the address matches an alias in the destination domain. For this purpose, an alias is considered to be any 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 name, IMail Server (a) processes the mail according to the settings for that list, and (b) checks the user IDs specified in the list settings.

- If there is not a match to any alias, IMail Server checks the user ID.

4. 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, the IMail Anti-Virus checks for infected messages as described in the next step. If you do not have IMail Anti-Virus installed, then the processing rules for list server mailing lists are checked.

5. Processing Rules for a list-server mailing list. If the message matches the rule criteria for a list, processing follows according to the rule. If not, then the message is sent to the list server. If the message is not addressed to a list, Forwarding is checked.

6. Forwarding. IMail Server determines whether an address is present in the Forward box on the General tab for this account. If so, IMail Server forwards the mail. If not, the mail is delivered to the user ID according to the established processing rules.

7. Processing rules for the mail host. IMail Server determines if the message matches a rule for the mail host. If so, then processing follows according to that rule. If not, then rules for the user ID are checked.

8. Processing 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 processing follows according to the rule. If not, then the Info Manager is checked.

9. Info Manager. IMail Server determines whether the user ID has the Info Manager enabled. If so, the message is delivered to the location specified in the Info Manager. If not, the vacation setting is checked.

10. 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.