All working OK but suddenly a message with an attachment refuses to arrive at its destination. It has no images, no bad language or anything like that, simply business English.
I have tried copying the text and pasting it to the bottom of my message and sending - same result.
My correspondent and I exchange messages all the time.
squarebear - it's not necessary to use an email client for email, it can all be done by going to the online site using a browser e.g. https://mail.google.com/mail
Yes, Thunderbird. Sorry. Not v good on the technical stuff, no matter how elementary. And if you have seen my other query about a hesitant cursor, it happened here too.