Hi Any spelling mistake in the part after @ might result in this error. Could the germankithen part be missing something? For example, perhaps you meant @germankitchen.co - the company based in Devon? Or, could the .co need something more after .co, like .co.uk? If you believe those things are correct, can you receive emails from people sending from that domain and check whether using Reply works for you? Cheers, Agnes

Hi

Thaks for your reply. The domain ends .co snd is correct

Yes i can receive but not i cannot reply and send or just send

Ok. Next basic checks:

1) Are outgoing emails and replies to other domains working for you?

2) If you are able, test whether you can send email to that problem address a) from your webmail (i.e. same account but not using Thunderbird), or b) from another account, such as a personal (Yahoo/Gmail/Live etc) email account.

If 1) is yes, and 2) is no, then the problem is probably not with Thunderbird.

If you get the same error response when sending to that address from outside mail systems, the problem is probably with that company servers or domain setup. It could be possible if the system is new, that the germankithen.co domain and email system is not fully set up yet. Or that the new domain has not yet 'spread' to all domain name servers (DNS), so your SMTP server can't find it yet, but this should cure itself in a short time.

If you are internal to germankithen.co and the problem only happens when sending to others inside the same company, I suggest you talk to the company IT support. It may be that that they need to check the setup for routing internal traffic.

Best wishes, Agnes