Zentyal as intermediate mail server

[mundor]

Hello, I'm trying to do the following in Zentyal and I don´t know if it is possible, I hope you can help me as it is my first experience with Zentyal and I'm a little lost.

The company where I work has contracted with an ISP a domain and a number of POP3 accounts for users hosted on the server of the ISP under our control. Some users have configured on their pcs accounts in Outlook, so far so good.

The problem comes because many users receive spam emails and viruses and I want to use Zentyal as an itermediate server to filter all the incoming and outgoing mails but always keeping the accounts hosted on the server of the ISP and using Webmail for incorporating Zentyal users to receive and send their mail.

Thank you.

[christian]

Webmail vs. plain mail client doesn't impact your target design, at least here. so, yes, you can go with webmail.
If I understand your point, I would propose this:

- as external PO3 mailboxes exist and you want to keep it, enable transparent POP3 proxy and active "filter spam" and "filter proxy"

- for outgoing mail, be sure to have enabled SMTP filtering options. It may make sense to prevent users to directly access their current "external" SMTP server so that they have to use Zentyal et benefit from such service.

[mundor]

I did what you told me to do but I have problems. If I create a domain “mydomain.com” in Zentyal, which is the same that I have in the ISP, Zentyal doesn´t send the emails with that domain to my ISP, I guess he thinks: “why am I go to send an email to my domain?” And the problem is that not all my email accounts of mydomain.com will be configured on my Zentyal server.

Can I make that Zentyal send emails to the SMTP of my ISP server? And how would you do it?

To download mail from the POP accounts in my ISP, do I have to do it as an external mail account for each user of Zentyal?

[christian]

Exactly what I told you: if you set-up gmx.at mail domain, then mail sent outside to this destination will not be sent.
I've currently no availability but I'll build something on test server as soon as I can, playing with aliases.

I don't understand your question about POP mail download. Currently, Zentyal mail retrieval is configured in "user corner", per account.

[EddieA]

- as external PO3 mailboxes exist and you want to keep it, enable transparent POP3 proxy and active "filter spam" and "filter proxy"

My understanding of this, is that the users still configure POP to pull from the ISP, and Zentyal "intercepts" the request, does the mail retrieval and optionally spam, AV scanning, etc, before passing the mail on to the requestor.

I don't understand your question about POP mail download. Currently, Zentyal mail retrieval is configured in "user corner", per account.

Isn't this configuration used when Zentyal pulls the mail from the ISP, and then the uses configure Zentyal as their POP server to get mail.

Or, quite possibly, have I misunderstood one or other of the mail retrieval options.

Cheers.

[christian]

I share your understanding about transparent POP. This works 

Then Mundor has other kind of request that is mixing use of internal mail infrastructure to send mail outside but also inside... for some users only, and, I suppose, with one account per user.

[mundor]

Thanks for your help but I think you don’t understand what I want to do. I’ll try to explain it with an example.

I have Zentyal configured with the domain xyz.com. I have a domain on an external server with the same domain name xyz.com. If I send an email abc@domain.com Zentyal sends the mail out. But if I send another email to abc@xyz.com Zentyal doesn´t send this email because he sees that i´m sending an email out to xyz.com when Zentyal is xyz.com. This is the error I get:

SMTP Error (550): Failed to set sender "correo2@xyz.com" (5.1.1: Recipient address rejected: User unknown in virtual mailbox table)

[christian]

Your mistake is to think that you can have internal mail server and external mail server for same domain without side effect.
If having xyz.com internally is not mandatory, change it and this will solve your problem