Using Postfix as a Backup MX

Previous Topic Next Topic
 
classic Classic list List threaded Threaded
8 messages Options
Reply | Threaded
Open this post in threaded view
|

Using Postfix as a Backup MX

Linda Pagillo
Hi gang. I could have swore I sent this to the list days ago, but no one responded and I can't find the email I sent in my sent folder which is completely weird.

Anyway... I have a few Windows-based mail servers. I would like to set up Postfix as a backup MX server for the Windows servers. I have never done this with Postfix so I did a lot of research and what I believe to be the most complete instructions can be found at this link: https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.

Have any of you used these instructions? If yes, how thorough are they? If not, do any of you have any instructions, tips or tricks that you would not mind sharing with me?

All advice would be very much appreciated.

I hope all of you are safe and healthy.

Thanks.
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Matus UHLAR - fantomas
On 31.03.20 12:03, Linda Pagillo wrote:
>Hi gang. I could have swore I sent this to the list days ago, but no one
>responded and I can't find the email I sent in my sent folder which is
>completely weird.

three people responsed and discussed.
Check at https://marc.info/?t=158544886200002&r=1&w=2
also check your spam folder.

note that gmail sometimes drops mail without warning, we had similar problem
at the end of last year, some people got our invoices, some did not.


>Anyway... I have a few Windows-based mail servers. I would like to set up
>Postfix as a backup MX server for the Windows servers. I have never done
>this with Postfix so I did a lot of research and what I believe to be the
>most complete instructions can be found at this link:
>https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.
>
>
>Have any of you used these instructions? If yes, how thorough are they? If
>not, do any of you have any instructions, tips or tricks that you would not
>mind sharing with me?
>
>All advice would be very much appreciated.
>
>I hope all of you are safe and healthy.
>
>Thanks.

--
Matus UHLAR - fantomas, [hidden email] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Saving Private Ryan...
Private Ryan exists. Overwrite? (Y/N)
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Linda Pagillo
Thank you! Yeah, the email is not in my sent folder and I did not receive any of the responses, not even in my Spam folder. Thank again for sending this my way. I will check it out.

On Tue, Mar 31, 2020 at 12:37 PM Matus UHLAR - fantomas <[hidden email]> wrote:
On 31.03.20 12:03, Linda Pagillo wrote:
>Hi gang. I could have swore I sent this to the list days ago, but no one
>responded and I can't find the email I sent in my sent folder which is
>completely weird.

three people responsed and discussed.
Check at https://marc.info/?t=158544886200002&r=1&w=2
also check your spam folder.

note that gmail sometimes drops mail without warning, we had similar problem
at the end of last year, some people got our invoices, some did not.


>Anyway... I have a few Windows-based mail servers. I would like to set up
>Postfix as a backup MX server for the Windows servers. I have never done
>this with Postfix so I did a lot of research and what I believe to be the
>most complete instructions can be found at this link:
>https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.
>
>
>Have any of you used these instructions? If yes, how thorough are they? If
>not, do any of you have any instructions, tips or tricks that you would not
>mind sharing with me?
>
>All advice would be very much appreciated.
>
>I hope all of you are safe and healthy.
>
>Thanks.

--
Matus UHLAR - fantomas, [hidden email] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Saving Private Ryan...
Private Ryan exists. Overwrite? (Y/N)
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Ken Wright
In reply to this post by Linda Pagillo

Linda,

I used LinuxBabe's instructions and have been completely happy with the results.  She has a way of explaining things, and it makes sense, at least to me.  I do recommend you either copy-and-paste her code snippets or pay especial attention when you input them; I accidentally put a period where I should have put a comma and it kept my server from working properly.

Ken

On 3/31/20 1:03 PM, Linda Pagillo wrote:
Hi gang. I could have swore I sent this to the list days ago, but no one responded and I can't find the email I sent in my sent folder which is completely weird.

Anyway... I have a few Windows-based mail servers. I would like to set up Postfix as a backup MX server for the Windows servers. I have never done this with Postfix so I did a lot of research and what I believe to be the most complete instructions can be found at this link: https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.

Have any of you used these instructions? If yes, how thorough are they? If not, do any of you have any instructions, tips or tricks that you would not mind sharing with me?

All advice would be very much appreciated.

I hope all of you are safe and healthy.

Thanks.
-- 
Registered Linux user #483005

If you ever think international relations make sense, remember this:  
because a Serb shot an Austrian in Bosnia, Germany invaded Belgium.
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Linda Pagillo
A huge thanks to all of you for your valuable input. I appreciate it very much. I have considered the spam problem that I know will occur if I set this up. I was going to install Message Sniffer on the backup MX and use it in conjunction with SpamAssassin to try and block as much spam as possible. I'm still kicking around ideas at this point so nothing is in stone. I figure no matter what I choose, I will still need to have some kind of AV/AS programs running on it. Right now I'm using other Windows servers as the backup mx for my primary Windows mail servers. I wanted to try out Postfix for the backup MX because it's solid and trusted. Also, I would not need to purchase Windows licenses. It's always nice to save a few bucks when ya can ;)

Again everyone.. thank you so much and I hope all of you stay healthy and safe wherever you are in the world :)


On Tue, Mar 31, 2020 at 1:23 PM Ken Wright <[hidden email]> wrote:

Linda,

I used LinuxBabe's instructions and have been completely happy with the results.  She has a way of explaining things, and it makes sense, at least to me.  I do recommend you either copy-and-paste her code snippets or pay especial attention when you input them; I accidentally put a period where I should have put a comma and it kept my server from working properly.

Ken

On 3/31/20 1:03 PM, Linda Pagillo wrote:
Hi gang. I could have swore I sent this to the list days ago, but no one responded and I can't find the email I sent in my sent folder which is completely weird.

Anyway... I have a few Windows-based mail servers. I would like to set up Postfix as a backup MX server for the Windows servers. I have never done this with Postfix so I did a lot of research and what I believe to be the most complete instructions can be found at this link: https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.

Have any of you used these instructions? If yes, how thorough are they? If not, do any of you have any instructions, tips or tricks that you would not mind sharing with me?

All advice would be very much appreciated.

I hope all of you are safe and healthy.

Thanks.
-- 
Registered Linux user #483005

If you ever think international relations make sense, remember this:  
because a Serb shot an Austrian in Bosnia, Germany invaded Belgium.
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Linda Pagillo
Guys, I have another question. This is in reference to the response that Bob Proulx gave me. He said that, " One critical item is that the relay_recipient_maps must be kept in sync across all of the systems". Why is this critical?  

On Tue, Mar 31, 2020 at 1:58 PM Linda Pagillo <[hidden email]> wrote:
A huge thanks to all of you for your valuable input. I appreciate it very much. I have considered the spam problem that I know will occur if I set this up. I was going to install Message Sniffer on the backup MX and use it in conjunction with SpamAssassin to try and block as much spam as possible. I'm still kicking around ideas at this point so nothing is in stone. I figure no matter what I choose, I will still need to have some kind of AV/AS programs running on it. Right now I'm using other Windows servers as the backup mx for my primary Windows mail servers. I wanted to try out Postfix for the backup MX because it's solid and trusted. Also, I would not need to purchase Windows licenses. It's always nice to save a few bucks when ya can ;)

Again everyone.. thank you so much and I hope all of you stay healthy and safe wherever you are in the world :)


On Tue, Mar 31, 2020 at 1:23 PM Ken Wright <[hidden email]> wrote:

Linda,

I used LinuxBabe's instructions and have been completely happy with the results.  She has a way of explaining things, and it makes sense, at least to me.  I do recommend you either copy-and-paste her code snippets or pay especial attention when you input them; I accidentally put a period where I should have put a comma and it kept my server from working properly.

Ken

On 3/31/20 1:03 PM, Linda Pagillo wrote:
Hi gang. I could have swore I sent this to the list days ago, but no one responded and I can't find the email I sent in my sent folder which is completely weird.

Anyway... I have a few Windows-based mail servers. I would like to set up Postfix as a backup MX server for the Windows servers. I have never done this with Postfix so I did a lot of research and what I believe to be the most complete instructions can be found at this link: https://www.linuxbabe.com/mail-server/how-to-set-up-a-backup-email-server-postfix-ubuntu.

Have any of you used these instructions? If yes, how thorough are they? If not, do any of you have any instructions, tips or tricks that you would not mind sharing with me?

All advice would be very much appreciated.

I hope all of you are safe and healthy.

Thanks.
-- 
Registered Linux user #483005

If you ever think international relations make sense, remember this:  
because a Serb shot an Austrian in Bosnia, Germany invaded Belgium.
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Matus UHLAR - fantomas
On 31.03.20 16:59, Linda Pagillo wrote:
>Guys, I have another question. This is in reference to the response that
>Bob Proulx gave me. He said that, " One critical item is that the
>relay_recipient_maps must be kept in sync across all of the systems". Why
>is this critical?

It's partly described at
http://www.postfix.org/postconf.5.html#relay_recipient_maps

many spammers try to use backup MX servers to deliver spam.

If your backup MX accepts spam that your primary MX would rejects because of
non-existent user, your backup MX would need to send back bounce, which
whould make it spam source, and it could appear on blacklists.

Dropping such mail is not a good thing, since that mail could get "lost"
where sender believe mail was accepted (by backup MX), while recipient would
not see it (because it was refused by primary MX).

Thus, knowing users is crucial to have.

I persinally believe that if you really need backup MX, you should do at
least some kind of recipient verification.

--
Matus UHLAR - fantomas, [hidden email] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Windows 2000: 640 MB ought to be enough for anybody
Reply | Threaded
Open this post in threaded view
|

Re: Using Postfix as a Backup MX

Linda Pagillo
Thank you for the clarification Matus. I appreciate it!

On Wed, Apr 1, 2020 at 5:31 AM Matus UHLAR - fantomas <[hidden email]> wrote:
On 31.03.20 16:59, Linda Pagillo wrote:
>Guys, I have another question. This is in reference to the response that
>Bob Proulx gave me. He said that, " One critical item is that the
>relay_recipient_maps must be kept in sync across all of the systems". Why
>is this critical?

It's partly described at
http://www.postfix.org/postconf.5.html#relay_recipient_maps

many spammers try to use backup MX servers to deliver spam.

If your backup MX accepts spam that your primary MX would rejects because of
non-existent user, your backup MX would need to send back bounce, which
whould make it spam source, and it could appear on blacklists.

Dropping such mail is not a good thing, since that mail could get "lost"
where sender believe mail was accepted (by backup MX), while recipient would
not see it (because it was refused by primary MX).

Thus, knowing users is crucial to have.

I persinally believe that if you really need backup MX, you should do at
least some kind of recipient verification.

--
Matus UHLAR - fantomas, [hidden email] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Windows 2000: 640 MB ought to be enough for anybody