Update: The issue seems to have been resolved and Laposte say they’re no longer sending the 519 responses as of April 25th 2018. Laposte.net are having a bad couple of weeks. There’ve been reports from customers of their IMAP service being unusable, with attempts to move or delete messages timing out and expected emails simply not arriving. Several delivery friends have mentioned that...
April 18, 2018
Laposte rejections
18April