Do I need to wrap email messages longer than 72 characters in a line?

Question

Occasionally I've seen code wrapping email messages to make sure a single line is no more than 72 characters long. Is there really need for this and what is this all about?

Answer 1

RFC 2822 contains this text about line lengths, which is where this likely comes from:

There are two limits that this standard places on the number of
characters in a line. Each line of characters MUST be no more than 998 characters, and SHOULD be no more than 78 characters, excluding the CRLF.

The 998 character limit is due to limitations in many implementations
which send, receive, or store Internet Message Format messages that simply cannot handle more than 998 characters on a line. Receiving
implementations would do well to handle an arbitrarily large number
of characters in a line for robustness sake. However, there are so many implementations which (in compliance with the transport requirements of [RFC2821]) do not accept messages containing more than 1000 character including the CR and LF per line, it is important for implementations not to create such messages.

The more conservative 78 character recommendation is to accommodate
the many implementations of user interfaces that display these
messages which may truncate, or disastrously wrap, the display of
more than 78 characters per line, in spite of the fact that such
implementations are non-conformant to the intent of this specification (and that of [RFC2821] if they actually cause information to be lost). Again, even though this limitation is put on messages, it is encumbant upon implementations which display messages