Re: [exim] Using verify sender

On 23 May 2011, at 13:13, Graham Butler wrote:

> I am currently looking into adding 'require verify = sender', with no callouts, to our Exim configuration. Unfortunately, my manager went to a conference last week and was informed that adding 'verify sender' was not very wise and could lead to the rejection of legitimate emails.
>
> From my understanding,' verify sender' is 'confined to verifying that the domain is registered in the DNS' with either a MX or an 'A' address. Rejecting such emails I would have thought would be good practice. I would agree that using 'verify sender' with callout is bad practice.
>
> Is the use of 'verify sender' recommended, and can anybody who has included 'verify sender' give any feed back on any problems they have experienced regarding rejections of legitimate emails.

I quite often investigate problems with sender verification callouts (a few times a month, perhaps). Only very occasionally are they due to an undeliverable domain. An undeliverable email address in a return path is invalid, for whatever reason.

> Graham Butler
> Infrastructure Team.
> The University of Huddersfield
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