Outgoing spam filter blocking email

[#1]

Hi,

I have received an email from a person I have been dealing with for months, but cannot reply or forward it. I get the message code 552 MSTlonSwb9a4kMSTmo36T0.

Seems the outgoing email spam filters have been updated recently?? 

Please advise how to overcome this.

Thankyou

[#2]

Hey @chatman,

I'm really sorry for the delay in getting back to you about this. Typically this type of error code would pop up if the email is too large - did you have any attachments added onto your reply?

[#3]

This is almost certainly the outbound spam filter.

We'd need a full copy of the email you're trying to forward along with message headers to look into it further.

If you don't mind private messaging me with the detail then I'll take a quick look. 

[#4]

I believe I have narrowed this down to an email address the spam filters don't like.

I have sent from one of my email addresses to another of my email addresses (so they are OK) and the only thing in the body of the email was jo.bloggs@leedsday.co.uk

There is no Jo.bloggs, that was just a test.

The same thing is OK when I sent it from gmail.

Seems @leedsday is the problem??? 

[#5]

I've checked that domain in isolation and it's coming back clean.

Could be the full email address I guess if you fancy messaging me that?

[#6]

Hi again,

I have checked this twice this evening and there seems to be no longer any problem.

Don't know why - this makes no sense to me.

Anyway, thanks for looking at this, and I hope I don't have to worry you again.

Many thanks

Chatman