i'm receiving emails but when I try to open previous emails they are encrypted and I cannot read them.
I am able to send and receive emails. When I try to read an email previously sent or received on Thunderbird, it is encrypted and cannot be read. We are using Earthlink as our email host. I called them and went through all the settings. I am able to send and receive emails on the Earthlink Webmail. I am also able to go to past emails on Earthlink Webmail and they are not encrypted. So the problem has to be with my Thunderbird mail program. I'm attaching a copy of an email that was sent to me on 1/24 that I was able to read, but when I went back to read it today, it looked like this.
تمام جوابات (3)
It looked like what?
How do you determine messages in your Inbox are encrypted?
It looks like this......
JVBERi0xLjcKNCAwIG9iago8PAovVHlwZSAvUGFnZQovUmVzb3VyY2VzCjw8Ci9YT2JqZWN0Cjw8 IC9QQUdFMDAwMSA3IDAgUiA+PgovUHJvY1NldCA2IDAgUgo+PgovTWVkaWFCb3ggWyAwIDAgNzky IDYxMl0KL1BhcmVudCAzIDAgUgovQ29udGVudHMgNSAwIFIKPj4KZW5kb2JqCjUgMCBvYmoKPDwK L0xlbmd0aCA0Mwo+PgpzdHJlYW0KcQo3ODkuMSAwIDAgNjEwLjYgMS40IDAuNyBjbQovUEFHRTAw MDEgRG8KUQplbmRzdHJlYW0KZW5kb2JqCjYgMCBvYmoKWy9QREYgL0ltYWdlQl0KZW5kb2JqCjcg MCBvYmoKPDwKL1R5cGUgL1hPYmplY3QKL1N1YnR5cGUgL0ltYWdlCi9OYW1lIC9QQUdFMDAwMQov V2lkdGggMjE5MgovSGVpZ2h0IDE2OTYKL0JpdHNQZXJDb21wb25lbnQgMQovQ29sb3JTcGFjZSAv RGV2aWNlR3JheQovRmlsdGVyIC9DQ0lUVEZheERlY29kZQovRGVjb2RlUGFybXMKPDwKL0sgLTEg L0NvbHVtbnMgIDIxOTIgL1Jvd3MgIDE2OTYKPj4KL0xlbmd0aCA4IDAgUgo+PgpzdHJlYW0NCv// ///KaWkdjFRDVg+05QGUXK2BlbVlGRWwosERHArI4hmhEviIjKaUswBglAHhzCE7CLUjHKHIHCUZ xINQ5Y5UiwqSzo7hBNHHPBVlAyhxRKAPzaEiaOyaiw1bBIFI7I6I7I6I6I6suijJ8zRhGMkAUBGK SnJjiQ23PBQMo54Ks+1BRUUJlFZTQUv+kEmR5sj0M+FojsFCChuYRjngpy3Kg9ZQ5VlWItggQlBR xxERESGpZSlEeLFIER1SBEf9f2kEELI80CCBBAkECBBhEUc45Q5cRBBCCMOc5zmwqDwIkFPZgSGm
That isn't really conclusive. It could also be an encoded attachment. Note, there's a difference in between encoded, and encrypted.
If you're able to open and view messages on the server, it is virtually impossible they do get encrypted on the way to your computer or by Thunderbird. Whatever your problem is, it is highly unlikely to me encryption is the cause.
You can try to rebuild the index file of the troubled folder. Right-click the folder - Properties - Repair Folder