Sophos XG Email attachments larger than 1mb is blocked

That is a known behavior and Support can resolve this for you. Please ping your case id to one of the support engineers to lift your limitation to 10 mb. 

I know this is a temporary fix, what is the long term solution? Is the issue confined to a particular hardware version, why only one of his many clients? Is the issue confined to outlook or any mobile mail application?

ian

See: https://community.sophos.com/sophos-xg-firewall/f/discussions/129163/sophos-xg-waf-exchange-201x-problem-with-attachment-size-greater-1-mb/474239#474239

So ive turned off the filter: scan outgoing emails and afterwards the problem is solved. Im not sure why the problem only exists on mobile devices with the mail/Outlook app but its working now 

Edit for other people with same Problem : Go to Emails, General Settings and scroll down to the bottom, deactivate :"Scan outgoing emails"

In this post is just said that the problem is solved but not how it got solved and what the original issue was....

Thank you, but that is WAF, not mail scanning as in this case. Also does the fix stick after a software upgrade.

ian

Do you use the reverse proxy? 

No, just smtp and Imaps scanning in a mail specific rule. 
ian

In my case i dont use reverser Proxy, as rfcat_vk said its smtp and pop3 in a general rule with any services 

In my case i dont use reverser Proxy, as rfcat_vk said its smtp and pop3 in a general rule with any services