Can’t send emails

[Troyt]

Hi suddenly I don’t seem to be able to send emails  - I receive a message saying- 

Cannot Send Mail

The username or password for

tho—————————— .uk

is incorrect 

—————————

OK           Settings

—————————

I’ve then reset my password - can anyone help please ? 
thanks

[Gondola]

Hi Troyt 

This will be a legacy domain from those inherited by TalkTalk from the pipex era? Which domain? Is the address a master address or an alias address which some of those legacy email addresses are. If it's an alias address then the password change must be carried out only on the master address.

Can you sign in to TalkTalk Mail webmail and send successfully from there?

Select here:  Sign in to TalkTalk Mail

Enter your full TalkTalk Mail email address, select Continue and enter the password, select Sign in.