SMTP EHLO blocks and allow-list

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Joined: Mon Feb 22, 2021 8:30 pm

SMTP EHLO blocks and allow-list

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It appears that EHLO blocks do not honor allow-listed (whitelist) IPs -- is this by design?

SMTP > EHLO BLOCK(?) > WHITELIST(?) seems to be the order connections are processed on SMTP --

We have this block [*.*.*.*] which protects us from a TON of login attemps -- but we have several users with devices that don't identify with a hostname and instead use EHLO [IPv6:::ffff:###.###.###.###] -- and we were attempting to allow-list their IPs but this fails due to processing order.

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Location: Melbourne, Victoria, Australia

Re: SMTP EHLO blocks and allow-list

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Sorry, it is just a straight block, without any exception possible. The whitelist of IPs only avoids RDNS, PTR check, greylisting and SPF checks.

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