cPanel version 62 - Horde Webmail Client Email Error Message - Only RSET accepted now
Thank you for letting us know and with the clues you supplied I was able to figure it out right away ... not the cure but the issue and indeed I was correct it is from the recent WHM/cPanel update https://forums.cpanel.net/threads/horde-unable-to-send-an-email-with-an-attachment-over-1mb.590239/ and WHM/cPanel themselves have an open ticket on the issue Internal case CPANEL-10763 is open to address the issue where sending an email via Horde on with an attachment 1MB in size or larger results in the following error message on systems using cPanel version 62
The only thing I can suggest until WHM/cPanel fixes this is to use one of the other web mail clients i.e. Squirrel Mail or Round Cube as the issue seems to be just with Horde.
When this issue is resolved it will be added to cPanel version 62 change logs here:
Monday, February 6, 2017
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