SMTP Error: Message size exceeds server limit

You seems got this error at Roundcube or Horde.

Here is explanation how it works:

Supposedly you’re trying to send message with an attachment file 44M

And you have the message_size_limit set in 50M as explained here

And you will not be able to send such message because attachments in a message are encoded by base64

It means your message will be by 30% bigger than expected, please see below calculation


You cannot send such message due to the limit in 50M, so you need either rise message_size_limit or upload and share your attachment to services like Gdrive/Dropbox/etc… Read the rest

cPanel error. Horde is unavailable while the system is being upgraded. HTTP error 503

Make sure hostname is good:


Did you run /scripts/upcp –force? If not do it.

/scripts/upcp --force

If you run it already, run it again as I got this fixed after the second run.

If still not working:

cd /var/cpanel/.application-locks
rm -fv UpdateHostname\:USERNAME
/usr/local/cpanel/bin/update_horde_config --user=USERNAME

where USERNAME is cPanel username.… Read the rest

How to enable Inline HTML display in Horde

cPanel’s Horde has “Inline HTML” is disabled by default

The error you probably got:

This message part contains HTML data, but inline HTML display is disabled.
View HTML data in new window.
Convert HTML data to plain text and view in new window.
Read the rest

How to enable Inline HTML message viewing for Horde.

By default HTML viewing message for Horde is disabled

To enable edit the following file


And change the following line


$mime_drivers['imp']['plain']['inline'] = false;


$mime_drivers['imp']['plain']['inline'] = true;

Syntaxis has been little bit changed, so now you need to update the following section in /usr/local/cpanel/base/horde/imp/config/mime_drivers.php… Read the rest