dovecot - Oct 2020 - Looking for a guide to collect all e-mail from the ISP mail server

>>> That way your users can create their vacancies with the ISP portal,
>> But then internal e-mails need to go out to the ISP,
>> don't they? Because, if internal e-mails get delivered locally, the
>> vacation autoresponses on the ISP will not trigger, will they?
> Hello R, I only wrote about the incoming side - of course, you also want to
> send mail to remote users, and that includes users with an address of 
> ?@myisp.com. They will go to the ISP and be fetched to local from there.

That is not what I had in mind. My users will not go to the ISP and fetch their
e-mails from there. They will always go to my internal mail server. If
a user is on the road, he/she will connect with OpenVPN first.

Of course, immediately receiving new e-mails without a VPN connection would be
more comfortable. But that level of comfort needs a real mail server
consultant then. 8-)


 >> The trouble is, with that configuration, if the Internet link goes
down,
 >> internal e-mail stops working too.
> And if internet's down, e-mail will stop working anyways, so why
bother?
> Even facebook/whatsupp will stop working then!

I have seen Microsoft Exchange setups that carried on working locally if the
Internet connection was down. If Microsoft can do that, I want to have it
too. 8-)

Whatsapp (which you shouldn't actually use for confidential business
communications) may continue working with your mobile phone data connection.

> With some tinkering, you can configure your local relay smtp to deliver
those locally,
> but if your people do not talk about their vacancies over the 
> water cooler, then they will miss that reminder then.

People are not that careless even in small businesses, where there is no water
cooler at all. Most of them do set up autoresponders, so that customers
know. Small business tend to care about customers more than big ones. The idea
is that those autoresponders should also work internally.

I just learnt that you can install a "Managesieve server" plug-in for
forwarding and autoresponders. That would be the way to go then, instead of
using the autoresponder at the ISP.


Best regards,
   rdiez

Am 26.10.20 um 11:24 schrieb R. Diez:
> 
>> Hello R, I only wrote about the incoming side - of course, you also 
>> want to
>> send mail to remote users, and that includes users with an address of 
>> ?@myisp.com. They will go to the ISP and be fetched to local from
there.
> 
> 
> That is not what I had in mind. My users will not go to the ISP and 
> fetch their e-mails from there. They will always go to my internal mail 
> server. If a user is on the road, he/she will connect with OpenVPN first.
Probably I could have said that better: fetchmail will fetch those mails 
from the ISP, same as any other mails to someone at your.site - the Inbox 
at your ISPs will always be empty, your users will only interact with 
the dovecot instance on premise. There is some inefficiency, the price 
for a simpler setup.
> I have seen Microsoft Exchange setups that carried on working locally if 
> the Internet connection was down. If Microsoft can do that, I want to 
> have it too. 8-)
>> With some tinkering, you can configure your local relay smtp to 
>> deliver those locally,
To be more clear - if you have a local smtpd too (not just dovecot and 
fetchmail, postfix perhaps), that sits between your users MUA and your 
ISPs smtpd, you can make it recognise someone at your.site as a
"local"
account and have those mails delivered locally. You have to set up some 
mappings though, that replicate the ones in your fetchmailrc.

Start of a HOWTO:

1) Install dovecot, create virtual accounts for all of your users
2) Install fetchmail, make it pull the ISPs IMAP and deliver locally
3) Install postfix as a smart relay and deliver locally to locals

Feel free to fill in the details ;)

-- 
peter

> Start of a HOWTO:
> 
> 1) Install dovecot, create virtual accounts for all of your users
> 2) Install fetchmail, make it pull the ISPs IMAP and deliver locally
> 3) Install postfix as a smart relay and deliver locally to locals
> 
> Feel free to fill in the details ;)
And I thought you guys had nothing else to do, sitting here on the mailing list
and pretending to have some mail server skills... So, yes, it does
look like I'll have to be the one filling in all the details!  8-)

Regards,
   rdiez