Formatting email addresses

[Guest]

When a piece of software that I have forwards an email to Outlook for sending
out. Outlook seems to be appending an apostrophe to the end of the email
address when it gets the email. (i.e (e-mail address removed)') How is it doing that?
Where can I go to re-configure that setting?

 

[DL]

I'd check yr coding; the apostrophe is likely a result of a coding error