email hacking attempt?

[Robert Heller]

At Mon, 01 Mar 2021 09:10:13 +0000 dave at thefletchers.net, "Ubuntu user technical support, not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> I keep getting from time to time rejection entries in my postfix logs
> of the following kind:-
> 
> Feb 28 13:47:05 ServerIV postfix/smtpd[37050]: NOQUEUE: reject: RCPT
> from sender48-eu-west-1-p.emailage.com[52.212.158.48]: 550 5.1.1 <
> 5ea11ebd64854dfbbe03377e at thefletchers.net>: Recipient address rejected:
> User unknown in local recipient table; from=<smtp at emailage.com> to=<
> 5ea11ebd64854dfbbe03377e at thefletchers.net> proto=SMTP
> helo=<emailage.com>
> 
> This is obviously never going to be a valid email address so I wonder
> what is going on here? Are these attempting to exploit some known
> buffer overflow or other flaw in a mail server?

The sender is just "guessing" E-Mail addresses.  It is not uncommon to use a 
wildcard address for virtual E-Mail addresses in the /etc/postfix/virtual 
table.

> 
> Just curious so I thought I'd ask as the list seems to be a little more
> quiet today.
> 
> Dave
> 
> 

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