I think I've figured this out so I'll share it here in the hopes it will help people prevent the loss of emails which is entirely frustrating

The email system appears to have a total character and space limit of 1024.

I think this includes the subject and sender tag added by the system to the end of the email, and am positive it's multiplied by every recipient you add to the send list.

So if you write an email that contains 350 characters and spaces, then send it to three contacts, it will fail, everyone gets a blank message and you get a system message saying Error, reason: succeeded.

Even if you try to CC yourself to save your email, what you get in return is blank.

I /ccr'd this in the hopes there may be someway to get the system to generate another message to the sender with the contents of their email so the sender would at least not lose their work. But I'm not sure this is possible. Perhaps they can at least change the error message so the user understands why it happened.

I suggest you draft your emails in something like MSWord and paste it in using the cntrl + insert command ingame. This way your work is protected and you can use the word count feature to get an idea of how many times you can CC the message.

Currently, I also cannot create new emails. The send button remains gray and the email can't be sent. So I have to reply to an exisitng email, change the subject, recipients and wipe out all the existing text in the message.