First thing I would do is log into your account at your providers web mail page and see if it is going into another folder besides the Inbox, like a spam folder. If it is not in your inbox on the providers server Thunderbird does not download it. As for no notification to the sender that is a function of your providers server and not a Thunderbird problem.

Airmail, thank you for trying to help but I'm confused by "log into your account providers web mail page"?? I have logged into Isqft and double checked my email address which is correct. I don't have a spam folder in Thunderbird. Are you talking about logging into GoDaddy? Which I think hosts our email and website? Where would I find an spam folder in there if there isn't one in my Thunderbird? Sorry....I don't understand how all these different providers work together.

If I understand this correctly, and I think I do

Mail is sent from isqft to godaddy and downloaded into Thunderbird.

So Godddy is your mail provider. Thunderbird is a mail client which either downloads mail from your provider (POP) or displays a synchronized view of the account on the server (IMAP)

So the points are. J* ust as the ostal service makes no guarantee of delivery, neither does email. Delivery rates may be well over 99% but there ar no ghuarantees and no requirements for godaddy to send notifications to the sender if they decide to quietly drop the mail.

• About the only thing that affects mail from the server to Thunderbird is anti virus/SPAM tools/ Security software. This usually masquerades as some sort of Internet security suite. Disabling these products from interfering in mail is often needed to get things working correctly. However I doubt this is the issue here.

• Godaddy subscribes to many blacklisting services, it is quite probably our sender is listed on one of them. See https://www.rackaid.com/blog/godaddy-blacklist/

It is very very unlikely this is a Thunderbird issue. If the mail appears in the inbox on the server when you log in, then it might be. But I don't think they make it that far.

Whoever hosts your email should have a webmail page and you should know how to access it for times like this. I know nothing about your mail host so I cannot say if it is Go Daddy. Hopefully you know who your mail provider is. Thunderbird is email client software that you use to connect to your mail providers server and manage your mail. It downloads messages that actually make it into your Inbox on the providers server. If they do not get to that Inbox then ask your provider for help figuring out why.