16 May
2014
16 May
'14
10:24 p.m.
Quoting Oscar del Rio <delrio@mie.utoronto.ca>:
On 05/13/14 03:02 PM, Stephan Bosch wrote:
Use of NULL envelope sender is generally recommended to prevent mail loops
Unfortunately, many servers out there reject emails with NULL sender. Some recent examples (real server names edited) :
Any domain hosted by RackSpace will reject a NULL sender for 'backscatter'.
Bascially, 'backscatter' blockers assume all edge SMTP servers will have complete knowledge of the final delivery status - during the SMTP conversation - thus labeling all NULL senders as forged spam redirected to them via a bounce message.
Rick