[NTLUG:Discuss] OT general email server question

[Fred James]

All
For a large portion of today my ISP's email service was nonfunctional - 
not sending/receiving
The error message, after asking for the password, was that the "server 
responded: authorization failed."
Is it correct to assume that the message was generated by my ISP's 
equipment, or could it be a generic message from my email client?
Thank you
Regards
Fred James

Additional detail:
    I have two email services ... my local ISP (A) and another ISP (B) ...
       A is set on my email client as the outgoing service
       A and B are each set as their own incoming service (of course)
    During the outage ...
       A could not send or receive
       B could both send and receive - even though it uses A to send