Re: [ietf-smtp] SMTP status codes 251 and 551

["Kurt Andersen (b)" <[e-mail]>]

On Mon, Feb 10, 2020 at 12:11 PM John Levine <[e-mail]> wrote:

>
> Another large change since the 1980s is that then most people read
> their mail on the same computer where the mail was stored, now nobody
> does and we all use IMAP.  So I've told the town people how to set up
> Gmail to collect mail from a mailbox here and switched back to local
> delivery.  That avoids nearly all of the delivery issues since there's
> no DMARC checks on fetched mail and for the most part it assumes that
> stuff being fetched is OK.
>

Seems like an interesting security/spearphishing hole - find someone who
receives mail on a system that might not be as aggressively filtered and
then reads it via another service which might not apply the same rigor or
warnings for fetched mail as it would for delivered mail. Of course most
mobile MUAs fall squarely into that latter category besides which security
items are the first things to be elided from the UX due to screen pixel
shortages.

--Kurt