Understanding Undeliverable Emails: Hard Bounce vs. Soft Bounce By CAS, Inc. | Central Address Systems Posted on November 1, 2016 Posted in Email, Hygiene Fatal error: Out of memory (allocated 716685312) (tried to allocate 20480 bytes) in /homepages/39/d295633752/htdocs/blogcasonlinecom/wp-includes/wp-db.php on line 1999