[v6ops] Re: SMTP IPv4 outage 1 July 2026

[S Moonesamy <[e-mail]>]

Hi Nick,
At 03:00 AM 03-07-2026, Nick Hilliard wrote:
>Sam Sargeant wrote on 02/07/2026 23:50:
>>On1 July 2026,  from 04:55Z to 20:10Z, IETF SMTP servers (25/tcp)
>>were unreachable over IPv4. For these 15 hours, messages addressed to
>>lists or aliases at ietf.org, irtf.org, iab.org, and rfc-editor.org
>>over IPv4 were not accepted.
>the internal wasp in me wonders how or why this would have been 
>service-affecting for anyone.

The duration of the outage was 15 hours and 15 minutes.  The 
timeframe of the outage intersects with standard working day in North 
America or Europe.  There wasn't any publicly-accessible 
complaints.  Either nobody cared about the outage or nobody noticed it.

SMTP is not an interactive service, i.e. it's not like HTTPS where 
the user would see a an error message in the web browser stating that 
the site cannot be reached.  That might explain why nobody noticed the outage.

There wasn't any traffic from my side, to 2602:f977:800:f7f6::1 
(tcp/25) while the SMTP service was not reachable over IPv4.

Regards,
S. Moonesamy