Affects Version/s: 1.3
Fix Version/s: 1.3.1
EMAIL-98, header values now are folded by commons-email.
Unfortunately, they are folded twice: once in "Mail.addHeader" or "Mail.setHeaders", and once again in "Mail.buildMimeMessage()" while iterating over the headers.
This results (in our test cases) in corrupted mail header lines having additional blank lines between the first and second line of a folded value - and thus ends in corrupted mails (as all headers after the first blank line are threatened as mail-body-content).
As this renders "additional headers" useless in commons-mail and corrupts every mail having additionl headers with longer-than-folding-size values, i set the priority to blocker.
The fix seems to be easy: just fold either in addHeader and setHeaders, or in buildMimeMessage (but not in both).
My preferred solution would be to fold in buildMimeMessage, and to store the values "as-is" in addHeader and setHeaders so one is able to work with the plain values (if neccessary) until the mail is actually build and send.