Is there a problem with sending email today?

[#1]

Is there a problem with sending email today?
Getting rejections and disconnects from server even to another User on this account.

Maurice

[#2]

To test, I just sent a message via the Plusnet email servers to a non-Plusnet account without issue, then replied back to the Plusnet servers, again without issue.
While not very definitive, it's working in and out for me.

[#3]

Thanks Nibiru
The only difference my end is that I'm in a temporary location this week and accessing via a different WiFi network.  Receiving mail OK and have working FTP and access to a website I maintain.
Error message from Server
The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was~~~~~~~~~~~~~~~~~  Subject 'Connection success', Account: 'pop3.plus.net', Server: 'relay.plus.net', Protocol: SMTP, Server Response: '550 <ann@theoldpo.co.uk> recipient rejected - relay denied', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79
Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account: 'pop3.plus.net', Server: 'relay.plus.net', Protocol: SMTP, Port: 25, Secure(SSL): No, Error Number: 0x800CCC0F

[#4]

Are you using authenticated SMTP for sending?  If you're not on the PN network you need to make sure that you email program sends your username and password.

[#5]

Aargh!  Forgot about that - last used it 3 years ago! 
Now need to remember the password?

Maurice

[#6]

Thanks pwatson
Logged into Member Centre and changed the password.  Now seems to be working.