Joined: 06 Jun 2008 Posts: 8165 Location: East Dubuque, Illinois, USA
1000 bytes is the absolute limit for an SMTP email. I've sent and received emails with 1000 byte lines with no problems. RFC 2821 and 2822 are the guiding documents and can be found via Google.
Usually, the IEBGENER input is concatenated -- often header, body of the email, and the trailer (a single period on a line by itself). If your job has such a structure, you must update all of the concatenated data sets to use the same LRECL or the email won't go. If your changes removed the trailer, SMTP will not send the email -- the period on a line by itself to end the body is not optional.