sending it 'To' one of my email addresses, and 'Bcc' to everyone in my list

Are you using a mailing list, or are you sending the message to individual recipients? In the latter case you may hit a limit imposed by your email provider. If in doubt, check with your email provider about such a limit or other possible causes for the error message you get. It may well be a temporary server problem.

I'm just specifying a long list of recipients' email addresses in the bcc field. This has always worked in the past, but as of yesterday (and today) it does not. I have posted the question on my ISP's email support forum.

By an extremely tedious process of doing a repeated binary chop on the list I've narrowed it down to one particular email address which was causing the problem. So the error message is just wrong.

I'd still be interested to know whether Thunderbird logs errors and/or provides a way to get at error information.

My ISP asked me to try sending via WebMail to see what happens. For the record - it fails to send and briefly pops up the error SMTP Error (452): Failed to add recipient "[email protected]" (... temporary failure). (Obviously I haven't replicated the actual email address there). Which at least is more useful in that it tells me the email address associated with the problem, although the error (452) actually does mean "Too many emails sent or too many recipients: more in general, a server storage limit exceeded." so Thunderbird is correctly reporting it, kind of, it just isn't telling me the email address associated with the error which would have saved me a whole load of bother.

If I try to ping the domain name part of the email address then it fails (could not find host - i.e. no DNS resolution for that name). But here's the strange thing, if I use WebMail to try and send to a completely fabricated domain name (pingpongpo.co.uk) then I get a different error: SMTP Error (550): Failed to add recipient "[email protected]" <[email protected]> recipient rejected - domain has no delivery address (DNS MX or A record)).

The domain name in the failed 'real' email address certainly used to exist, so it seems that there is some different behaviour from from my ISP's mail servers depending on whether it's a now-defunct-domain-name or a never-existed-domain-name.

But whatever, if Thunderbird had reported the email address associated with the error (assuming that information is available to it, it certainly is using the ISP's webmail) then it would have been obvious from the start. Which is why I was wondering if there are any error logs or ways of getting all of the information associated with an error.

MikeBz said

But whatever, if Thunderbird had reported the email address associated with the error (assuming that information is available to it, it certainly is using the ISP's webmail) then it would have been obvious from the start. Which is why I was wondering if there are any error logs or ways of getting all of the information associated with an error.

Two things.

1. Thunderbird reports the errors it gets from the mail server verbatim. So if the level of information is inadequate, this is an issue for you to address with your ISP.

2. Thunderbird is not using your providers web mail. Web mail and the protocols that are used for mail clients are similar in some ways. Similar to you choosing to send a package with DHL and another with the post office. Both will take your package, both will get it there. (usually) But that is about where the similarity ends. Stating that one delivered and one did not does not prove anything about the failed delivery. Same goes for SMTP sending and web mail sending.

I see a lot of error messages, the first in your first subject is indicative of trying to send an email and not actually entering the password for the SMTP server.

Then there is one about a failure to add a recipient. That should mean that the server just could not do it's job, and send to the address specified. IT could also mean that you have a list of recipients that exceeds the limit imposed by your sender. You identify it as a long list in BCC. Lots of providers just limit that long list to an arbitrary figure say 20. as you do not mention who provides your mail service actual limits can not be researched.,

As detailed above, I narrowed it down to a single recipient whose domain name appears to have gone AWOL - so nothing to do with sending to a list of addresses.

I appreciate that Thunderbird doesn't use my provider's Webmail - as far as I'm aware Webmail is just a web interface onto my mailbox, is it a stretch to think that when you send email from your ISP's webmail it uses the same SMTP server as you configure for any other mail client? Certainly using both the Webmail interface and Thunderbird the ISP returns the wrong error code (452 not 550) when I send to this particular email address, it's just that in the webmail case the error message also contains the email address which I would have thought it must be getting back from the SMTP server but that's an assumption obviously.

Anyway my ISP are looking into it.

Just tried the same thing from a different mail client (same SMTP server) and get a message saying the recipient (email address included) was rejected by the server, so there is some difference between clients' behaviour for what must be the same SMTP server behaviour.

Instead of using individual recipients you may want to use a mailing list. http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Create_Mailing_List

Note, you should also use Bcc: for a mailing list.

Thanks, that's helpful. (I do always Bcc the recipients).

Well after a lengthy exchange with my ISP (PlusNet) they tell me that "We've been advised that the error code is just a generic one that many different mail services use. It's clear in the wording what the exact problem is. Unfortunately there isn't anything we can do to change the error code our system advises of."

I've pointed out that the incorrect error code (452) coming back is not generic and certainly doesn't mean that the domain name in the email address is invalid or deceased. Hey-ho.

I'm not at all convinced that Thunderbird is giving me all of the information though, other mail clients do give me the duff email address from the server in this scenario.

My exchange with PlusNet support is here:

https://community.plus.net/t5/Email/Sending-small-message-but-get-quot-The-size-of-the-message-your/td-p/1623916/highlight/false

I am not convinced Thunderbird error reporting is as good as it could be either.

See my comment here https://bugzilla.mozilla.org/show_bug.cgi?id=1539239#c7

If you can still force the error a log, just as has been done in the bug might be handy. With two of them I will file a bug if there is relevant information missing that is in your log as well.

Thanks Matt, that does help in that I can see from the log what the offending email address is. It's a shame that Thunderbird doesn't present the offending email address with the error message, but at least now I know how to find it if it happens again. Here is the extract from the log (I've replaced the offending email address with "offending email address":

2019-03-29 08:04:14.825000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 5 2019-03-29 08:04:14.825000 UTC - [9164:Main Thread]: I/SMTP SMTP Send: RCPT TO:<offending email address> 2019-03-29 08:04:16.669000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 0 2019-03-29 08:04:16.669000 UTC - [9164:Main Thread]: I/SMTP SMTP Response: 452 ... temporary failure 2019-03-29 08:04:16.669000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 6

When the send is successful it looks like this:

2019-03-29 08:04:14.809000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 5 2019-03-29 08:04:14.809000 UTC - [9164:Main Thread]: I/SMTP SMTP Send: RCPT TO:<good email address> 2019-03-29 08:04:14.825000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 0 2019-03-29 08:04:14.825000 UTC - [9164:Main Thread]: I/SMTP SMTP Response: 250 <good email address> recipient ok 2019-03-29 08:04:14.825000 UTC - [9164:Main Thread]: I/SMTP SMTP entering state: 6

So a bit of a double whammy - PlusNet server returning the wrong error code and Thunderbird not displaying the email address with the error reported for it.

Could you email that log to me at [email protected]