internal email relay problem

I get this error, when I check the receive connector log

Remote(SocketError)

It might be a message or an attachment size limit

Or an anti-virus solution which is throwing an error.. Check your logs.

As Hello There mentions...

If any SMTP MTA between your sender + recipient has a size threshold less than your attachment size, then your message won't be delivered.

As bleeuwen mentions, refer to your sending logs + also your receiver logs (if you're running the receiving MTA) for the exact reason for the failure.

Tip: Regarding logs, better to test, measure + know, than guess. Always refer to your logs for reasons for failures.

Tip: You can also use SWAKS to send your message on the command line, to see every step of your SMTP conversation in realtime, including any errors.

I would look on your Receive connector you are using for Relay and see what the maximum size limit is.

Hi All,

thanks for all the help and infos.
I could check it in powershell with send-mailmessage

This email with attachment was received :-)