Congestion on outgoing mailserver

[tasker]

Periodically when sending emails through smtp.o2.co.uk my email client (Thunderbird) gives an error message "An error occured sending mail: The mail server sent an incorrect greeting: mail.o2.co.uk Service not available - too busy."

This can happen on several attempts and then finally the message gets sent. The problem seems to be occuring more frequently of late.

I have taken it up with Customer Services and they just deny there is any problem with capacity on their outgoing mailservers, but my experience suggests otherwise.

Is anyone else encountering this problem?

[Tony1044]

Have you tried it with any other mail client?

I don't use Thunderbird, but I believe under the advanced settings, you can extend the timeout?

Might be worth upping to say 60s? It may not be the actual mail servers that are timing out.

Edit: Yes, you can change the timeout settings: http://www.freeemailtutorials.com/mo...cedOptions.cwd

[tasker]

Thanks for this comment.

The problem is not with the timeout because the error message appears immediately I try to send the email, not after 60 seconds.

What appears to be happening is the O2's mailserver is refusing the connection at once, saying it is "too busy".

I have not tried to reproduce this with other email clients, but will do so.

[Tony1044]

Intriguing.

I assume that if you tried it with, say a gmail account, it would work fine?

Certainly sounds like there might be a problem with the actual mail gateway.

I don't use the O2 mail servers, so forgive me if this is duff info* - are you using a secure (SSL / Encrypted) connection? If you aren't, it might be worth swapping and if you are it might be worth disabling to see if either helps.

On the face of it, though, it sounds like a plain old simple overloading of their server - can you tie it down to any particular time of day?

*I say it might be duff, because some ISP's mandate secure connections for mail and won't allow unencrypted connections, but not using them, I don't actually know if that's the case with O2. Sorry.