Outgoing mail from Thunderbird to the BT Mail SMTP server

[cj_rupp]

Hi,

I'm getting an intermittent failure using a BT (btinternet.com) account in Mozilla Thunderbird. Most of these instances are under Windows 11 with 128.5.1esr (64-bit) Thunderbird.

What happens is that Thunderbird fails to connect with the SMTP server for outgoing emails with the correct password. This fault is not always present, but recently it has been present more than it has been absent. I have matched all the server setting for BT email that I can find, and I believe the original setting were automatically set by Thunderbird from a template. So, I have to log in to BT email in a browser, copy the message and send it. So, there's nothing wrong with the email, just the link-up between Thunderbird and the SMTP server.

This is the main error message:

Sending of the message failed.
Unable to authenticate to Outgoing server (SMTP) . Please check the password and verify the 'Authentication method' in 'Account Settings | Outgoing server (SMTP)'.

I do check, but I haven't been able to find an error there. Hence, I assume that this may not be the true location of the problem.

Any suggestions what I could try next? (Let's assume that a different email client is not a useful answer.)

Thanks for any help. This has been going for several days now.

Cheers,

C. J.

[licquorice]

No idea why you would think suggesting a different client in order to eliminate Thunderbird is not a useful answer, but hey ho.

When the problem occurs, try disconnecting your broadband to force a change of IP address which will possibly result in connecting to a different SMTP server in the farm.

[gg30340]

Are you presently a BT Broadband customer or are you paying for your email through a BT Premium email account?

The correct settings are as per this link but if your email normally works with Thunderbird the settings should be correct.

https://www.bt.com/help/email/manage-email-account/manual-settings/what-are-the-settings-for-outgoin...

[cj_rupp]

Hi,

I just meant that I don't regard dumping Thunderbird as a solution to Thunderbird connectivity problems. I may not have selected the best terminology.

The suggested solution looks interesting, but I haven't had time to try it yet. Nevertheless, I'd be a bit annoyed, if the only solution turns out to be resorting to an element of randomness.

Cheers,

C. J.

[cj_rupp]

Hi,
Thanks, that confirms that my settings are correct.
Cheers,
C. J.

[licquorice]

I wasn't suggesting you dump Thunderbird, I was suggesting you tried a different client in parallel as part of the fault finding process.

[cj_rupp]

Hi,

I think I may have found the root of this problem, and it may have not a lot to do with BT Mail. I turned on the VPN and magically the BT Mail works, but I can't open a link to Amazon in the browser. If I turn off the VPN, Amazon works, but BT Mail doesn't. I'm using a Norton VPN, that's in a package I already paid for.

I've seen other comments that suggest that a VPN can switch your DNS settings, maybe that's related. I'm not going to pursue this further, as I have a workaround. However, this might be useful for reference. Maybe, this is an exceptional case where the VPN makes things possible, rather than blocking them. I would mark this as a solution, if there was a button for it.

Cheers,

C. J.

[cj_rupp]

Hi,

I think this thread has been marked as solved.

Can I re-open it?

I just tried to send an email from Thunderbird, with the recommended SMTP settings for BT Mail:

Port: 465

Security: SSL/TLS

or

Port:  587

Security: STARTTLS

in both cases authentication would be 'normal password'

The latter port setting appears in the AI overview. I haven't traced the original.

Anyway, both of these options are failing on my current machine. I think it might be an authentication timeout.

The "Solution" above was to turn on the Norton VPN. This machine has ESET and not Norton. So, I don't think I have a VPN option. I also don't believe that the requirement for a third party VPN is a "Solution". I'd say that's more of a temporary workaround.

I hope someone will look at this. If not, I may have to start a new thread.

Thanks for any help or advice.

Cheers,

C. J.

[gg30340]

The recommended settings are as per the following link

BT Email server settings | BT Help

You will note it does not use Port 587 or STARTTLS

I would also say that it is not necessary to use a VPN at any time. If anything a VPN could cause you issues as it will be showing your email account being activated from numerous different geographical locations and that may be seen as an account that has been compromised by the BT security systems.

[cj_rupp]

Hi,

Thanks for the advice I have received. I'm sure it was well-meant. I have tried to stick to the settings recommended for the BT Email SMTP interface: i.e. port: 465, security: SSL/TLS. I did try port: 587 with STARTTLS. This is suggested on the Google response to a 'BT Email SMTP server settings' search, but I have to admit I haven't seen it recommended on any page with BT branding on it.

Since the last posting, I tried changing the password for my BT email account. This has been suggested, as a general solution for email problems, but it didn't appear to solve anything.

I use both multiple email accounts and several machines, desktop, laptop, several tablets and phone, so changing the password was a bit of a pain.

This morning, I managed to get the error down to a connection 'rejected by policy'. At that point, I checked IP address for blacklisting, but all I could find there was a policy block list (PBL). Then, I thought you might be able to construct an explanation, by abductive reasoning:

If the IP address is rejected by policy, and is assigned to SKY, who probably don't need to send email via BT email, then that might be blocked, where the VPN link, presumably with an automatically generated IP address, which might be anonymous, would be allowed.

The problem with abduction is that it is fitting the "facts" to the evidence, with no test as to whether any of them are true. I still have the evidence that, trying to send email via the BT email SMTP server, fails unless the VPN is on. This evidence goes against all the advice offered as to the wisdom or pitfalls of using a VPN. It's just the wrong way round.

In the meantime, I had to reboot the machine. I'm now back to failure because of authentication failure or timeout. I don't have enough information about this to understand or remedy the situation.

I would still be grateful for any insights or advice. Thanks.

Cheers,

C. J.