Catchall and SMTP


please guys i am a new nethserver noob and needs help on catchall and smtp settings for NethServer 7

i am currently using SME 9.2 and for Catchall Mail Retrieval the setup is quite simple eg:
" Configuration > E-mail > Change e-mail reception settings "

i have read the article for Nethservr 7 on Howto setup a multidrop mail server V2 and need to understand if this is the way to download mail with a catchall account?
if yes, there is also an instruction on the same article to Configure the CentOS7 server.
do i also do as per that on my Nethserver 7?

For SME 9.2 SMTP it is also simple eg:
" Configuration > E-mail > Change e-mail delivery settings "

For Nethserver 7
is this is done under " Configuration > Email > Smarthost " Yes / No ?

any help greatly appreciated

Hello HuskyBob,
I wrote the guide you are referring to.
When I wrote the guide, Nethserver couldn’t download email from a multidrop POP3 mailbox and route it to different users. Each POP3 connector must go to a specific user. I’ve had a look on the POP3 connector in the current Neth7 web console and it still routes POP3 accounts to specific users.
It still appears as though Neth7 does not support Multidrop POP3 for getting email from your ISP mail server.

The guide Howto setup a multidrop mail server V2 configures a separate linux server on your network to get the email from your ISP multidrop POP3 account and then route it to your NethServers email system. It’s a bit of a hack (needing two servers to run a basic email system) but it does work.




I can confirm that POP3 connector works, but you need to set up each Mail account separately.
But it works fairly well.

My 2 cents

…that got me thinking. I used to have my ISP filter my email into different users (which had their own POP3 logins) and a catchall user (which had its own POP3 login). I then had lots of POP3 connectors configured to download mail from each ISP mailbox and deliver it to the user on the local machine. The ISP catchall mail box would go to a specific user on the local machine.
However, I think the Neth POP3 connector bypasses the RSPAM filter.



POP3 should still be considered a crutch, using catchall or not.


  • Spam detection is less efficient or bypassed
  • Clunky
  • Complicated

But sometimes there are no alternatives.
My home provider won’t open up SMTP or Reverse DNS, required for a full working mail server. So at home I also use POP3 connector.

5 accounts, which is what i use here, is “handleable”, 5 POP3 connectors. Sending is done by an account on my external provider’s host called smtpuser. Smarthost on NethServer handles this. I don’t need to pick up any mail here, but I do, if just for provider’s status reports or problems with sending.

Don’t get the idea I can’t handle mail/dns, I have about 20-30 NethServers up and running (also as mailserver) with full DNS resolution (forward and backwards, internal and external).

My 2 cents

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It would be nice if NethServer had an out of the box MultiDrop POP3 connector, that did proper antispam filtering. Perhaps a Dev could put this on their to-do list.

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thank you all for your input, much appreciated

i was really hoping to just have ONE system to download and manage mail

hopefully there is a solution to this in the near future

On the contrarary. POP3 catchall is the simplest reliablle mail solution. You get prefiltering from the provider, attack prevention from the provider, you need no fixed ip address, not DNS entries, there are not problems when the server is down because the provider catches the email. Spam detection also works quite nice. I am using POP3 catchall for years with many mailboxes and there are no problems.

It be a really good thing, if Nethserver supports catchall. All other small business solution also support this.


You ONLY get spam prefiltering from the provider, if that works and is adaptable. For my provider not really usable.

NethServer’s spam detection is more or less sidelined, a lot of tests are bypassed.

You still need to make sure DNS is correct, otherwise you can send some mail, more of what you send will not be sent, due to being classified as spam (The first sending smtp is not resolveable to recieving smtp servers) and a lot more.

I maintain: It’s still a crutch!

A real mailserver has a fixed IP, and is resolveable in DNS, forwards and backwards!
If you don’t believe me, see the RFCs and Wikipedia…

But even POP3 retrievable has reasons where it can / should / must be used.
I am using POP3 retrievable, eg fore friends Home servers. The only company/client of mine using this has the LEAST reliable mail! (Provider issues…).

Then again, POP3 retrievable is NOT the same as catchall. Catchall tends to transfer more junk.

My 2 cents

The big problem - at least in Germany - is that fixed IP addresses are rarely available, so it is not possible to use the direct SMTP-server on Nethserver. Even not with Dyndns, since mail could be delivered to wrong servers during the dailay ip-change.

All standard domain and email hosters just give you POP3 and a SMTP smart host for receiving and sending mails.

Yes, prefiltering spam doesn’t work very good and should be done by the receiving server (i.e. Nethserver). With prefiltering I meant DOS and mail bomb attacks, which do not reach your server. But this is only a side point.

The main problem is the unavaiablility of fixed IPs, especially if you use several domains.


We have the almost same situation here in Switzerland. To get a real fixed IP, you need a “business” line from your provider, usually much more expensive (we’re talking 5 to 10 times MORE expensive!).
THE big advantage with a business line here is you get either a 1:1, 1:2 or 1:4 download/upload ratio, rather than the usual 1:10 with consumer lines…

There are a few providers which give you almost a fixed IP even for consumer accounts. The only thing is reverse DNS can’t be entered, but otherwise all works.
But, not possible with my cable provider, so I also use POP retrieval at home…
This usually entails a surcharge here of 10-20 CHF / Month.

Another BIG difference Germany / Switzerland is that here, an IP change is not forced daily. Even without a fixed IP, you often keep the same IP until you need to reboot, or a local power outage (can be several weeks!)…

True, DOS Attacks don’t reach your Server, but that has nothing to do with “filtering”…
That’s just a “deflector”, if you want to give it a name…

You CAN easily use a single IP for several Domains, I have several customers using this…
And it’s not just web, with name based domain hosting. Just think how many domains in Germany use T-Online Mailserver as Domain Mail… :slight_smile:

Hosted servers aren’t always treated really professionally. I have one case of several hosted VMs at a hoster in Switzerland. They internally “moved” the servers during Corona Lockdown, with the result that those servers could ping (Google), but not even internal or external DNS servers could be reached. And this for 4 weeks! No updating possible for the hosted NethServer! Really bad!

My 2 cents