Outgoing mail formatting on PGP

Dear All,
I have a problem with outgoing mails.
I chose to send the encrypted email as “Inline”. the problem is, received
email is non-formatted and there is no “br” tag between lines. also when i
tried to decrypt it by envelope, I’ve got the "Unknown ASCII armor type"
error that I think related to text formatting and missed characters.

Could you please advise me on this issue?

Best regards,