Outgoing failures.
WHAT TO ESTABLISH FIRST
Does receiving work? Does webmail send?
IF WEBMAIL SENDS
The problem is your client configuration.
THE MOST COMMON CAUSES
Outgoing authentication not enabled Wrong outgoing port Wrong encryption setting Your network blocking the port
THE AUTHENTICATION POINT
Your client must authenticate to send.
Many clients disable this by default.
FOR PORT BLOCKING
Some networks block the standard outgoing port.
Try the alternative port cPanel lists, or test on mobile data.
IF WEBMAIL ALSO FAILS
Check the sending limit: accounts have hourly limits
Check the message size Read the exact error
FOR A SPECIFIC RECIPIENT ONLY
The recipient's server is rejecting it.
Read the bounce. It usually states why.
FOR "SENDER NOT AUTHORISED"
An SPF problem. Check Email Deliverability.
WHAT TO SEND US
The full bounce message, not a summary.
