Messaging interfaces returned unknown error

[guest]

When I uncheck "Used cached mode" then it works.

However if I have a draft saved with an email that I tried to send previously, why does it append =SMTP: in front of each email address?
I can't even delete the =SMTP: It highlights the whole address. I have to copy it into notepad and remove it there, and paste back into the address or cc fields in Outlook.