Exchange and antispam problems

[ivicav 0]

I have two problems regarding Anti-spam feature i Mail Security.

 

First problem is that Anti-spam Engine catches mails from my own organization and quarantine them with no obvious reason. Normal textual mails without attachments are filtered.

 

I found after some investigation that it is happening when someone from my organization goes home or somewhere other than our location and try to use outlook client to send e-mail. If public IP of their provider is on some blacklist their mail is quarantined even they are authenticated as they should and mail is send to other mailbox inside our organization. I have no idea why ESET check IP address of mail client instead only of mail server sending mail but it does.

 

Other problem is regarding mails coming from someone hosting their emails on Office365 platform. Their mails are ALWAYS ended in quarantine no matter what I do. I even tried to set Allowed domain to IP list with all Office365 IP address ranges I could find but with no luck at all. Tried to add their emails as permitted senders also no luck. Tried to set their domain as permitted Domain senders also nope. Exchange Online Protection mark them as non spam mails but ESET always keep them in quarantine.

 

Problem is that we have a lot of partners using Office365 so I ended up looking every once awhile to Mailbox quarantine which is highly unacceptable not to mention senseless.

 

I am starting to be VERY frustrated. I also contacted our support for ESET in Croatia 10 days ago and send them all of requested logs but they are still silent.

 

[filips 44]

To see the reason why antispam catches your emails check Mail server protection log (in GUI go to Log Files and choose "Mail server protection").

The problem you describe sounds like antispam using client's IP address - did you enable "Advanced settings/Mail transport protection/Advanced settings/Search for sender's originating IP address in headers"?

You can check Mail server protection log to see why the messages from Office365 are moved to quarantine

[ivicav 0]

Thanks for help. I will try to disable this setting.

 

Regarding Office365 all I got is this:

 

Mail was reclassified from UNKNOWN to SPAM by blocklist

[filips 44]

Please disable "Search for sender's originating IP address in headers" and check if it helps - hopefully it will solve also problems with Office365.

"Search for sender's originating IP address in headers" is intended only for servers that are behind a gateway that hides the original SMTP connection IP address.

[ivicav 0]

That is it. Thanks, you saved me a lot of time.