Problems sending e-mails to t-online customers: Unknown user

[Rene2009]

Hi community,

I have problems sending e-mails to customers from t-online (very big german provider).

I got the following error message:

Translated from german:
Thunderbird error:
Error during sending the message: The mail server replies: Unknown user.
Please check the e-mail address myname@t-online.de and repeat the process.

Outlook 2000 error:
The message could not be send, because the recipient from the e-mail was rejected by the server.
Server replies: 550 Unknown user ... Error code:0x800ccc79.

Problem:
This e-mail address is coming from the customer.
We only press the reply button in the e-mail client.

Also the reply e-mail address is the same than the e-mail address from where the customer has send the e-mail.

We´ve also tried it with Outlook and with Thunderbird 3.0.

We´ve also tried to write a new plain e-mail.

It´s not working.

Then we use our e-mail system inside our ERP System with the same e-mail (without HMS).

It works.


Possible causes:

The E-mail format in the e-mail clients is like this:

my name <my.name@t-online.de> like

mr. smith <mr.smith@t-online.de>

Can this format be a problem in combination with t-online and HMS?


Because the e-mail could be sent correctly by our ERP-System, I believe that HMS is the problem.

Best regards,

Rene

[Rene2009]

Hi again,

I´ve tried to copy the log from HMS into this forum, but I can´t copy the log to the clipboard.

How can I do this?

Maybe in the next HMS version, we need a copy button.

Best regards,

Rene

[Tezcatlipoca]

The log is just a basic text document. You can open it in Notepad and copy/paste the relevant section, or, if you want to attach the whole log, go to reply, and click the Browse button just below where you make your reply. Point it at the hmailserver_<whichever date>.log file and click to upload.

[mattg]

Because the e-mail could be sent correctly by our ERP-System, I believe that HMS is the problem.

Did you reply the same as you did with the hmailserver client?

My guess is that the email you receive has an incorrect 'reply to' address...
Can you check the header of such a message that you receive, and look for the 'reply to' address and compare that to the 'from' address?

[^DooM^]

Open up the log file in the logs directory and copy and paste that is sufficient, there is no need to add a copy / paste function to hMail.

I just tested this by adding an account called me.smith@mydomain.com and sent emails every which way i could think of, with and without dots and quotes and <> brackets and every time hMail accepted and delivered them. So either you have some kind of SMTP inspection going on at your firewall, or AV (Specifically mcaffee) or you are running ASSP / Spam Assassin or it's not being sent through hMail.