Thunderbird does not send emails to one address

[cullism]

Messages I send to my brother are not sent. I ask for Delivery Verification but I don't get it and my brother does not receive the email. I am able st send him emails via my Yahoo and Gmail addresses as well as my ISP's webmail, just not Thunedrbird. Any explanations?

[DanRaisch]

You don't say it but may we assume that you are able to send messages to correspondents other than your brother?
Were you able to send to that address using Thunderbird previously and this problem has just started?
How are you sending the messages to your brother? Do the messages include images or HTML formatted text?
Are there copies of these messages to your brother in Thunderbird's Sent folder?
How is the account set up in Thunderbird, as POP or IMAP? Find out using menu path Tools->Account Settings->Server Settings->Server Type at the top right of the dialogue.

[tanstaafl]

Try sending a one word plain text message (to minimize the chances of the problem being due to a over aggressive spam filter) using the Gmail account in Thunderbird, CC'ing yourself at your Yahoo account. Use view -> message source and look at the headers in your copy of the sent message at the Yahoo account. Look for any headers that begin with X-Spam such as X-Spam-score: and X-Spam-hits: to see what issues Yahoo might have had with the message.

[cullism]

DanRaisch, yes, it is only this one address to which I cannot send emails. About six weeks ago I found that I could not send emails to most of my family. What they had in common was that they all had our family name as part of their addresses. I reinstalled Thunderbird which may or may not explain why it is only the one address which doesn't receive my emails now. I have sent numerous messages to that address which contain only "Test" as Subject and in the body of the message. Copies appear in the Sent folder, however I don't receive delivery notifications. I have tried sending test messages from all four of my email addresses with the same result. The account is set up as IMAP. I then added Gmail to Thunderbird which my brother received.

[cullism]

I tried an experiment. I sent the same email to my brother via Thunderbird, Optus Webmail and Mailbird. None were delivered.

[tanstaafl]

So you can send him mail by yahoo webmail, gmail webmail and your ISP webmail accounts but not using Thunderbird, Mailbird or Optus Webmail. What is he using to receive the message - a ISP webmail account?

You also said you couldn't send mail to most of your family, which used your family name as part of the address. Are you sending it to generic webmail accounts which share a string (family name) with a ISP or are you paying for a custom domain name? Some background information on what addresses (don't need the actual email addresses) you are trying to send to would help.

Does the email address you are sending to have any 8bit characters as part of the name?

[BruceAWittmeier]

Don't know if this has been resolved or not but have you possibly copied his email address from a successful of sent mail? Just thinking the email address is incorrect in the TB address book. Spaces do not work in email addresses and do not show up in a display...meaning it could be there but not seen. Just a thought.