Noel Jones:
> Jan P. Kessler wrote:
> > 1. Will check_sender_mx_access lookup an a record if there is no mx
> > record for a given sender domain? I guess it won't as there's
> > reject_unknown_sender but I'd prefer to be sure.
> 
> If there's no MX, the sender domain's A record will be used. 
> If there's no A record either, then there's no lookup.

That's correct. check_sender_mx_access attempts to do what
the SMTP client does, and not what I wrote earlier.

        Wietse

> > 2. Is there a maximum number of mx records that will be checked by
> > postfix? Are there any standards requiring or recommending this? Just to
> > prevent trivial DoS attempts by setting up domains with hundred of mx
> > records.
> 
> The max is however many MX hosts fit in 32k.  I've seen some 
> domains with hundreds of MX records (one for each host in a 
> /24).  This hasn't caused any noticeable  problem.
> 
> 
> PS. looks as if your workstation clock is 1h fast.
> 
>    -- Noel Jones
> 
> 

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