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address as displayed by the recipient's mail application. SPF can help defending SPAM
and malware sent with forged sender address.
If you decide to publish a restrictive SPF entry for your own
domains, the filter will also reject inbound emails pretending to
be sent from your own domain. If SX-GATE directly delivers
outbound emails, you should make sure that it uses a valid
HELO name. It can be configured in menu "Modules > Mail
Server > SMTP settings" on tab "Delivery parameters". Instead
of publishing an SPF entry for your own domain you could enable
option "Reject mails sent with own domain as sender" on tab
"Sanity checks".
SPF may cause problems with emails forwarded by a third part.
Please carefully consider the information provided for option
"Accepted hosts".
The SPF filter checks inbound emails only. So it won't check emails received from IPs
from the list "Local IP addresses" in menu "Modules > Mail Server > SMTP settings" on
tab "Relay control". Also authenticated emails and emails composed with SX-GATE's
webmail client will not be checked.
SPF can only be effective if inbound emails are delivered directly
to SX-GATE with SMTP. Particularely if emails are polled from
a POP server, SPF is useless.
Check SPF
Enable the SPF check with this switch.
Accepted hosts
The SPF filter won't process inbound emails from IPs configured as "Local IP
addresses" on tab "Relay control" in menu "Modules > Mail Server > SMTP settings".
However it is often necessary to whitelist additional addresses:
Backup MX
If a backup MX is configured for your own domain, the SX-GATE SPF filter must
not process emails it receives from the backup MX. This is because the backup
MX is not an authorized sender in the terms of SPF for the sender domain.