On 17/12/2019 17:45, Tim Streater wrote:
In article , Martin Brown
wrote:

On 17/12/2019 12:46, Tim Streater wrote:
In article , The Natural Philosopher
wrote:

On 17/12/2019 12:10, Broadback wrote:
On 17/12/2019 11:49, The Natural Philosopher wrote:
On 17/12/2019 10:05, Broadback wrote:
I recently switched from Plus net to BT. I have my own domain so
that when I move internet supplier I can keep the same email
addresses. This has worked fine in the past but now BT will not
let me communicate with Hotmail addresses. Why, and is there a
way around this problem?

Why are you using BT at all?
Use PlusNets smtp relay for outgoing.
= smtp.plus.net

Because I wish to. I never used Plusnet other than for internet. I
use, and have for years, Thunderbird, it is only BT as an internet
provider

My bad, you switched to BT FROM plus net.

Ah. And are you using BT's relay?

And why is the use of Thunderbird or any other particular email client
relevant?

Thunderbird does have the odd bug if the mail server is tardy in
responding or there is a mismatch in security certificates.

What are security certificates?

The certificate that assures you that you are talking securely to your
selected mailserver and not to some man-in-the-middle attacker.

The bug is that in certain circumstances the security settings override
can get lost. I think the trigger is a timeout somewhere in the chain.

--
Regards,
Martin Brown