Email Security.cloud

As many other people on this forum we are having troubles delivering mail to our customers that are using Symantec cloud services, since all our messages (sent by Office365) are rejected with the same reason:

Remote Server returned '554 5.0.0 <server-26.tower-239.messagelabs.com #5.0.350 smtp;550 5.0.350 Remote server returned an error -> 553 Message filtered. Refer to the Troubleshooting page at;http://www.symanteccloud.com/troubleshooting for more;information. (#5.7.1)>'

We have tried to send a sample message to investigation@review.symantec.com, as suggested by technical articles (like https://support.symantec.com/en_US/article.TECH250089.html) and by some Symantec fanboy on this forum, but the result is ironically:

Remote Server returned '554 5.1.2 < #5.1.2 smtp; 554 5.1.2 Recipient address rejected: User unknown>'

This is really annoying, is there anyone from Symantec who can do something about it or is this forum left on his own ?

Hello Sergio,

This looks like a False Positive verdict, in such instances, please follow those guidelines to submit to submit us the email for review :

https://support.symantec.com/en_US/article.TECH233678.html

Please make sure to forward the email as attachment, and not attaching the email to another manually, as we need the headers to be preserved.

After the email is submitted, detection should be amended within 24H. However there won't be any feedback sent your way, should you require one, you'll need to contact the administrators of one of the domains you are trying to contact. They will be able to reach our Support to get further details.

Note that contacting the administrators of the receiving domain, in such instances, is the expected path to resolution, according to IT best practices.

Have a nice day!

Best regards,

Guillaume Pietkiewicz, Pr. Product Support Engineer

Hello Guillaume, thanks for the information ant the link provided. I agree that "contacting the administrators of the receiving domain, in such instances, is the expected path to resolution", but how am I supposed to do that if all our emails to that domain get filtered ?

Best regards

Sergio

Hello again Sergio,

Contacting the administrators in such instances can be complicated if you do not have an established professional relationship between your 2 entities. If you do work with them, you or your users reporting the issue should have means to contact, via phone for example, someone on the receiving side, which can link you to their own IT admins.

On a more classical approach, you can leverage the RFC defined administrators addresses, in particular the postmaster address (RFC822, 6.3). RFCs dictate that emails to this address should be accepted, and directed to a mail administrator of the receiving domain for treatment. Hence you can, if you do not have any contact within your business partner organisation, leverage this email address to report your mail issues and have those addressed.

This last part was specifically designed, in RFCs, to allow administrators to reach their peers to have mail flow issues resolved.

I hope this helps.

Have a nice day!

Best regards,

Guillaume Pietkiewicz, Pr. Product Support Engineer

when that happens you should wait for response from the administrators to apply a resolution so you can indicate again the configuration of the emails you just have to follow the instructions in the link provided to you so that the staff of symantec attend the case as soon as possible possible so it has happened in the company where I worked previously and the problem after a day was solved.