Problems sending e-mail through Windows live mail.

[shirleyscott]

Hello,
The message could not be sent because the server rejected the sender's email address. The sender's email address was 'xxxxx@att.net'.

Subject 'Question'
Server Error: 450
Server Response: 450 Requested mail action not taken: mailbox unavailable
Server: 'outbound.att.net'
Windows Live Mail Error ID: 0x800CCC78
Protocol: SMTP
Port: 465
Secure(SSL): Yes
Thank You.

[tanstaafl]

The problem is the recipients mailbox was temporarily unavailable, for some unknown reason. One possibility is that your email provider black listed the recipients mail server (usually due to spam being sent from that server). Its possible the message you sent was too large for the recipient to receive it, the error text was too generic to tell and no secondary error code was provided. Another possibility is there was a routing error due to a router or SMTP server in the route taken to reach the recipients mailbox. If you are using a laptop you could try sending the message from somewhere else such as a library or coffee shop that might use a different ISP or path. Its also possible the problem was something wrong with the recipients mailbox.

I suggest you try sending a short plain text message with no attachment using webmail (browser based) to see if the problem is caused by the recipient or not. If that fails, then try sending a message a couple of days later. The '4' in 450 means its a temporary problem.

https://www.knownhost.com/wiki/email/tr ... or-numbers
https://wiki.mattrude.com/SMTP_Status_Codes