Description

According to the RFC 2822 specification (clause 2.1.1), the header length should be no more than 78 characters.

Each line of characters MUST be no more than 998 characters, and SHOULD be no more than 78 characters, excluding the CRLF.

According to the specification, the length of the ENTIRE LINE should not exceed 78 characters. Currently, the laminas-mail library only counts the length of a value of the header.

Reproducing the problem

$message = new Message();
$message->addFrom('matthew@example.org', 'Matthew Somelli');
$message->addTo('foobar@example.com');
$message->setSubject('xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx');
$message->setBody('This is the message body.');

echo $message->toString();

This code will return the following result.

Date: Thu, 21 Oct 2021 09:59:33 +0000
From: Matthew Somelli matthew@example.org
To: foobar@example.com
Subject: xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx

This is the message body.

As you can see from the example, the header is longer than 78 characters.

New code behavior

This commit has fixed this issue. In this pool request, the code above will return the following result.

Date: Thu, 21 Oct 2021 10:04:43 +0000
From: Matthew Somelli matthew@example.org
To: foobar@example.com
Subject: xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx xxxxx
xxxxx xxxxx

This is the message body.

Now, the title does not exceed 78 characters.

Note

Waiting for pooling request on laminas-mime