Looking for a guide to collect all e-mail from the ISP mail server

[Peter Blair]

At 25 October, 2020 R. Diez wrote:
> 
> I am too afraid, I would not expose any such port on the Internet. Who knows
> if the mail server stays months without an update. If I am to recommend or
> implement any such mail server solution to a small business, I would insist
> that the e-mail server is not exposed at all on the Internet.

Setting and forgetting any server/service to run unpatched for months is
generally a bad idea.  I presume that you won't be maintaining this for
them long term -- why not just point them at a hosting service like
google apps, and let google keep things up to date?