workaround for the 990 character limitation for email mailservers

php html-email mail-server character-limit

11,023

Solution 1

You can put your content through the wordwrap() function so that you don't manually have to insert newlines.

Have you considered using one of the many mail libraries available? PHPMailer, PEAR Mail, SwiftMailer, etc...?

Solution 2

Order servers have an even lower limit: 76 chars per line + \r\n.

You have to make use of the imap_8bit() and imap_binary() functions in order to convert your data to a base64 or quoted-printable encoding.

You can also use an existing library, like SwiftMailer.

Solution 3

Actually, this is not a "mail server" problem. The SMTP line limit dictates the number of characters allowed on each line during transmission. The SMTP RFC allows for up to 1000 characters per line, and default postfix installed cap at 998 characters. You should contact your hosting provider on increasing your SMTP line limit if you feel it's necessary to exceed the RFC.

11,023

Author by

Phill Pafford

Love development with PHP/Symfony/PHPStorm, iOS, PostgreSQL, Linux flavor Ubuntu, jQuery/Mobile, Foundation CSS, GitFlow AVH and HTML5 Personal Projects are Crypto Currencies, Home Automation, Mobile development, SMS/MMS and DIY electronics via Make and Hack A Day https://keybase.io/phillpafford https://onename.com/phillpafford #bitcoin: https://www.coinbase.com/phillpafford #DogeCoin: D67fwUKwKQQeL9pdbZmbWcevuAYW8XPqyz

Updated on August 01, 2022

Comments

Phill Pafford almost 2 years

Wanted to know if there are any functions/classes/etc.. to help with the 990 character limitation for email as my HTML is being effected due to this.

The Problem: (Source)

Note that mailservers have a 990-character limit on each line contained within an email message. If an email message is sent that contains lines longer than 990-characters, those lines will be subdivided by additional line ending characters, which can cause corruption in the email message, particularly for HTML content. To prevent this from occurring, add your own line-ending characters at appropriate locations within the email message to ensure that no lines are longer than 990 characters.

Anyone else seem to have this problem? and how did you fix this?

Sounds like I need to find a good place to split my HTML and manually add a line break, ugh...

UPDATE:

It's tablature data with many rows. So do I need to add a \n or <br /> somewhere?

UPDATE #2: Adding MIME Type Code

$headers  = "MIME-Version: 1.0" . "\r\n";
$headers .= "Content-type:text/html;charset=iso-8859-1\r\n";
$headers .= "Content-Transfer-Encoding: quoted-printable\r\n"; // added this, but still no results
$headers .= "From: [email protected]\r\n";

Here is how I'm calling the function(s):

How I originally called:

return $html;

What I tried:

return imap_8bit($html); // not working, nothing is captured in the error log

AND

return imap_binary($html); // not working, nothing is captured in the error log

UPDATE #3 (Adding Mail Function)

try {
    mail(
        '[email protected]',
        'Subject of Email',
        $html,
        $headers
        );
    } catch (Exception $e) {
        echo ("ERROR: Email NOT sent, Exception: ".$e->getMessage());
    }

Example HTML (This is the message of the HTML email) (This is also in a class that is part of a XMLRPC service)

private function getHTML() {
    $html  = '<html><head><title>Title</title></head><body>';
    $html .= '<table>';
    $html .= '<tr><td>many many rows like this</td></tr>';
    $html .= '<tr><td>many many rows like this</td></tr>';
    $html .= '<tr><td>many many rows like this</td></tr>';
    $html .= '<tr><td>many many rows like this</td></tr>';
    $html .= '<tr><td>many many rows like this</td></tr>';
    $html .= '</table>';
    $html .= '</body>';
    $html .= '</html>';

    return $html;
    //return imap_8bit($html); // not working, nothing is captured in the error log
    //return imap_binary($html); // not working, nothing is captured in the error log
    // Both of these return the XMLRPC Fault Exception: 651 Failed to parse response
}

Fault Exception: 651 Failed to parse response basically doesn't like the format or how the data is returned.

Phill Pafford over 13 years

I'm running this in a XMLRPC service and both imap_8bit() and imap_binary() crash. usage: return imap_8bit($html); instead of return $html; (same for imap_binary()). Am I using this right? and SwiftMailer is not an option right now as it would need to go through an approval process to be installed on a production server.
Alix Axel over 13 years

@Phill Pafford: You have to set the mime headers accordingly, I can't tell you if it's right without having a look at your code. Have you considered using SwiftMailer or any other email library, like PHPMailer?
Alix Axel over 13 years

@Phill: Try adding this additional header: Content-Transfer-Encoding: quoted-printable.
Phill Pafford over 13 years

updated my header to add the code (see main question), still no luck
Alix Axel over 13 years

@Phill: Ok, I need more info then. What do you mean "crashed"? How are you sending the email - using the built-in mail() function?
Phill Pafford over 13 years

wouldn't wordwrap() add the characters itself to the viewable html? The data is in a table with several rows of data, I'm not sure if adding the newline or <br /> would cause any display issues on how the data is formated
Yossi Gil over 13 years

@Phill Pafford, Unless he is using <pre> tags using wordwrap() to wrap the text won't impact the display. This is what we do at the ESP I work for, and it's how the mail libraries do it as well.
Alix Axel over 13 years

@Phill Pafford: Help me help you, bring some helpful context to the question. Where are you doing return $html;? And what did you mean by "crashed"? Any error output?
Phill Pafford over 13 years

ok I have added more to the main question, the XMLRPC doesn't offer much in the way of error codes and nothing shows up in the Apache error log as well.
Alix Axel over 13 years

@Phill Pafford: Ok, so the problem is how to escape chars within the XML, I'm not sure what the correct way to do that is. What happens if you base64_encode() your $html? Also, you may want to post a new question regarding the XML escaping since that has nothing to do with the SMTP email protocol.
Phill Pafford over 13 years

I think the wordwrap() might actually work, testing it now. BTW what is the default action if you just use wordwrap($html); with no parms? Looks to split the string only of spaces (which is what I would like and am testing for right now), just wanted to confirm
Yossi Gil over 13 years

@Phill Pafford, Correct, wordwrap($html) will just insert \n's into the string every 75 characters (or less, depending on wordbreaks.) It won't break words up.
SG1 over 12 years

I think this is the correct answer. I was getting spaces inserted after 990 characters in emails sent via php's mail() function. I added the following code (after this answer) and my problem went away: mail($to, $subject, wordwrap($message, 75, "\n", true), wordwrap($headers, 75, "\n", true))