The limit is total message per hour, so sending 5 in one batch and 16 in another will still exceed the limit. Once you have exceeded the limit I would assume it will be an hour before you can send again at all as you have tripped the limit.

Perhaps have a look at this https://www.lifewire.com/email-sending-limit-per-day-hotmail-1174265

They suggest that once you are on their radar the limit may be as low as 10. But really this is an issue between you and your mail provider. It has nothing at all to do with Thunderbird. Perhaps you could approach Microsoft for support with their mail service.

Matt - Hadn't sent any emails that day except the one to my normal list. Each time the message suggests I check a different email address on the list.

Matt - Hadn't sent any emails that day except the one to my normal list. Each time the message suggests I check a different email address on the list.

yes because that is where it is crapping out. But I can't really tell you what goes through the minds of people from Microsoft. They speak a different language to me.

I've contacted my provider (iinet) and they say everything is OK at their end. Are you saying it's a Microsoft problem?

I solved the problem by deleting the Mozilla Thunderbird folder, from C: drive program files folder (did not delete the profiles folder). then downloading and reinstalling Thunderbird. I followed DanRaisch's instructions: http://forums.mozillazine.org/viewtopic.php?f=39&t=3036593 Although I didn't disable my AVG anti-virus and I downloaded Thunderbird from a different website. His instructions: Uninstalling and reinstalling Thunderbird, if done correctly, would not remove either your emails or the account settings for your current accounts.

Clear the browser cache and the Windows Temp directory. Shutdown any anti-virus software you are running. Download a new copy of the full installer from http://www.mozillamessaging.com/en-US/thunderbird/ Delete the directory C:\Program Files\Mozilla Thunderbird Run the installer. Restart the anti-virus program.

Note that your saved messages, address books, settings, passwords, etc (if any) are stored in a different directory from the program files and will not be removed by deleting the directory identified above.

So you saying, you finally got AVG to work correctly? Congratulations.

Given a reinstall of the application does not affect any settings, data or other information used to connect to the server the reinstall will not have interfered or changed anything as far as Thunderbird is concerned. It might however prompt an anti virus product to configure itself correctly I guess. Does AVG still attempt to edit each outgoing mail to add an advertising line about scanning the email?

Do you have a VPN installed?

You misunderstood. I re-installed Thunderbird, not AVG. That solved the problem of no longer being able to send emails to my contact list (error message said I'd exceeded the maximum number allowed).