[Users] Unable to send messages

[Richard]

> Date: Sunday, March 13, 2022 05:57:22 +0800
> From: Bret Busby <bret.busby at gmail.com>
>
> On 13/03/2022, Paul <paul at claws-mail.org> wrote:
>> On Sun, 13 Mar 2022 05:01:18 +0800
>> Bret Busby <bret.busby at gmail.com> wrote:
>> 
>>> Why can't I send messages, while being able to receive messages?
>> 
>> What does the Network log say? (/Tools/Network Log)
>> 
>> with regards
>> 
>> Paul
> 

> 
> Network log;
> 
> "
> *Account '<email account>': Connecting to SMTP server:
> mail.<domainname>:25...
> ***mail.<domainname>:25: connection failed (Connection timed out).
> ***Error occurred while sending the message.
> "

It's unusual (now days) for a mail client (MUA) to connect to port 25
on the remote server to send mail. Generally it's either port 465 or
587 (depending on SSL/TLS settings). Are you certain that the port 25
is correct in your case? [On consumer-grade connectivity, port 25 is
often blocked by the ISP.]