Antivirus reset-both action for mail protocols

[BillKuo]

Hi!

We enable the blocking email viruses  attachement  by setting the antivirus profile with an action “reset-both” for SMTP.  The virus attachement could be blockded, however the sender’s mail server keep retry until timeout and no undelivered mail message returned to sender.

Please advice? Thank you!

Device : PA3050, PANOS 7.08

[pulukas]

For SMTP related functions you will want to set the action to "block".  This will send a SMTP 541 message to the sending server so it stops trying to deliver the message.

[Hithead]

hi,

you mean "drop"?..."block" is not available...

[SHKP]

Yes, "Block" action is not availiable anymore. I wondering it was related to response feature had been change. 

https://www.paloaltonetworks.com/documentation/70/pan-os/newfeaturesguide/content-inspection-feature...

[mivaldi]

Reset Client, Reset Server and Reset Both will all send an SMTP 541 message followed by the appropriate resets.

Reference:

https://live.paloaltonetworks.com/t5/Featured-Articles/Tips-amp-Tricks-Complete-Action-List-in-Profi...

[SARowe_NZ]

Hey,

The SMTP 541 official definition is:

541

The recipient address rejected your message: normally, it's an error caused by an anti-spam filter.

Your message has been detected and labeled as spam. You must ask the recipient to whitelist you

Can someone confirm that this will not cause the SMTP server to stop sending ALL email, and this action only drops the email containing the malware?

We receive all email from an upstream / external mail filtering/relay service and occassionally some viruses get through. We want to stop this at the firewall, but are concerned changing the default action on the AV profile will result in all mail from the external relay being stopped once an event is detected and the SMTP 541 response is sent.

Thanks,
Shannon

[Raido]

In case of SMTP protocol only email with virus will get 541 back. Others are not affected.

POP and IMAP don't have this capability built into the protocol.