So I have two accounts on my Thunderbird, business Microsoft Exchange and then a personal G-Mail account. Recently I have been having certain e-mails not being able to send through Microsoft Exchange. I have OWL support for both of them to work correctly. It is usually an e-mail over 8mb of attachments or some time it has been an e-mail with a lot of wording in the body, like lots of replies I have had to delete most of the info in the body to get it to send. If I send it through my G-Mail account it goes no problem. The Message it gives me is "Sending of the Message failed. The server had an internal error. This is always a problem of the server and not of you or your application." I tried to go online through office.com to send it that way, and it worked. My internet guy thinks it is Thunderbird but doesn't use it and really doesn't know anything about Thunderbird. Most of my guys that work on my business computers don't know anything about Thunderbird. My office manager has Thunderbird and is not having this problem. I am not the best with internet or mail configurations. This is getting frustrating. I am hoping someone know what the problem is and it is an easy fix. Please let me know if you have any ideas, I don't like outlook and some of the other apps for mail. I am used to Thunderbird and don't really want to learn a new one.