Cannot send emails using Thunderbird.

[#1]

Moved wifes emails to Thunderbird and can receive emails but can't send them.

Incoming and outgoing server settings are OK.

Email is to a domain that is hosted by plusnet and I have no issues with my emails thru the same domain on a different laptop using Thunderbird.

Router and ISP is not plusnet so I am using SMTP authentication - tried SSL/TLS & STARTTLS, normal password.

Not sure why, but Thunderbird asks for password when trying to send the email.

error message - The mail server responded <xxx@xxx.co.uk> sender rejected - invalid domain (no MX or A record)

Ran Telnet and got 235 authentication suceeded.

Can also send via webmail

Any ideas where I'm going wrong?

[#2]

Thunderbird has some oddities with configuring the SMTP server.  It is not a product I use, but I have fiddled with it.

Excellent testing using TELNET which proves that the userID and password were fine.

Email is to a domain that is hosted by plusnet

Where is the SENDING domain hosted?

Both you and the wife are sending as the same domain as in ...

• you@mydomain.co.uk
• wife@mydomain.co.uk

For the SMTP server login, what are you using for the wife's configuration

• wife@mydomain.co.uk
• wife@youraccount.plus.com
• youraccount+wife << preferred

The SMTP server is relay.plus.net port 587 encryption STARTTLS

Check the status of mydomain.co.uk here - MX Lookup Tool - Check your DNS MX Records online - MxToolbox

[#3]

Thunderbird has some oddities with configuring the SMTP server.  It is not a product I use, but I have fiddled with it.

Excellent testing using TELNET which proves that the userID and password were fine.

Email is to a domain that is hosted by plusnet

Where is the SENDING domain hosted? Same as the to domain - plusnet

Both you and the wife are sending as the same domain as in ...

• you@mydomain.co.uk
• wife@mydomain.co.uk Yes
  

For the SMTP server login, what are you using for the wife's configuration

• wife@mydomain.co.uk
• wife@youraccount.plus.com
• youraccount+wife << preferred This one
  

The SMTP server is relay.plus.net port 587 encryption STARTTLS Yes and also tried 465 SSL/TLS which works as my settings

Check the status of mydomain.co.uk here - MX Lookup Tool - Check your DNS MX Records online - MxToolbox

Results -  mx.avasin.plus.net, SMTP OK, Blacklist OK, No DMARC record found, DMARC Quarantine/Reject policy not enabled, DNS record found.

[#4]

See if anything here helps - How to Fix Thunderbird SMTP Error?

[#5]

@paul1098 if theres no luck from @Townman s link , then try setting Thunderbird to log smtp traffic https://kb.mozillazine.org/Session_logging_for_mail/news

[#6]

Thanks Townman,
I'll start working thru' the fixes and see if it gets resolved.

[#7]

@Townman 
Worked thru' those suggestions but nothing worked.

@MisterW 

Logged the smtp traffic but not sure what its telling me.

[#8]

@paul1098 post the log and we'll see if there's any clue

[#9]

@MisterW 

Read thru' the log and found the problem.

A simple punctuation mistake in the email address rather than any SMTP issues. Hence why every test you and @Townman had provided me came up OK.

I did spot it while carefully reading thru' the log so the logging did it's job.

Thanks for all the help and links you both provided.

[#10]

Sometimes the answer is the bit we are most confident about being right. It is always wise to check settings - wrong punctuation and spacing can create less than obvious issues - on some screens dot and comma can appear much the same. Asking users if they are sure they have typed it right can be seen as inflammatory … and thus be presumed as correct!

Delighted you have found the issue and are now sorted.

[#11]

True.

I hadn't appreciated the 2 step process in sending compared to the single process in receiving emails.

I'd assumed everything was OK because the user name and password were OK and I could receive emails.

I now see that the username is only to logon to the plusnet server and then the recipricants email server checks the email address and if either fails it returns an smtp error.

You never stop learning in this life.

Thanks again.