[SOLVED] Question about mail forwarding/relay/proxy

Teucrus

Active Member
Jul 7, 2018
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Hello,
I am kinda new in the world of email services. I would like to ask for some information if the setup I want to achieve is possible with PMG.
Here is what I have:
G Suite account.
Sendgrid Pro account.

My issue is that G suite IP addresses end up in blacklists and I have many outgoing emails ending up is SPAM although they are proper legitimate emails.
I will be using Sendgrid's service for email marketing and I have a dedicated IP address with them.

So I would like to use Sendgrid as an outboud gateway for g suite. The problem is that: Sendgrid requires SMTPauth but g suite is only relying on IP whitelisting.
What I want to do then is: Have PMG to sit between the two services and accept the outgoing email from g suite and forward/relay the mail to sendgrid.
What I cannot find in the documentation or at least I am not sure if it's the correct setting is where can I set PMG to send the outgoing emails through another smtp server.

Thank you for you time.
 
Thank you for your reply.
Gsuite is google's business gmail. So yes they are hosted in the cloud.
The IPs are blacklisted because they are shared with other clients.
I know the securirt oriented part of the PMG. That's why I wanted to use PMG to leverage that feature also.
So are you telling me the PMG cannot act as a releay?
 
What I want to do then is: Have PMG to sit between the two services and accept the outgoing email from g suite and forward/relay the mail to sendgrid.
Technically this should be possible:
- configure gsuite to send mail to PMGs internal port (allow their IP-ranges in the Networks of the Mail Proxy configuration)
- configure PMG to relay mails to sendgrid - for SMTP-AUTH you need to adapt the main.cf configuration template and add the account+password (there are quite a few threads here which describe this)

I do wonder that gsuite would be blacklisted in a large scale (given that many users are using google for mailin) though...

I hope this helps!
 
I do wonder that gsuite would be blacklisted in a large scale (given that many users are using google for mailin) though...
Well they work quite hard to unlist the IPs and rotate them but still if you monitor the IPs you see them poping in and out of blacklists.
This causes some of the emails getting to junk box.
We don't have a large amount of mails yet but it will become significant later. I see around 2% of the emails sent failing to hit inbox.
 
Thank you for your reply.
Gsuite is google's business gmail. So yes they are hosted in the cloud.
The IPs are blacklisted because they are shared with other clients.
I know the securirt oriented part of the PMG. That's why I wanted to use PMG to leverage that feature also.
So are you telling me the PMG cannot act as a releay?

Google should provide the maximum service uptime/availability since you as the customer have already paid for the service.

PMG is a great anti spam product but since GSuite already have it own anti spam function, it is just my own opinion that using a simple postfix relayhost is a much practical/simple option.
 
Google should provide the maximum service uptime/availability since you as the customer have already paid for the service.

PMG is a great anti spam product but since GSuite already have it own anti spam function, it is just my own opinion that using a simple postfix relayhost is a much practical/simple option.

The uptime/availability is not the issue here though. The inbox provider's filtering is. Currently the only outbound stats I have are what I get from DMARC, after using the relay I wan't to filter the outbound mails so I can find out what is causing them to go to junk (I expect that even with the dedicated IP address and the reverse DNS entry some emails will still end up in junk. I don't expect 100% inbox rate but as far as I can reduce the junk rate withough significant financial impact, it's a win).
Also setting up PMG is very simple for me since I am already using PVE and thus I can just deploy a CT with the PMG in it.
 
The uptime/availability is not the issue here though. The inbox provider's filtering is. Currently the only outbound stats I have are what I get from DMARC, after using the relay I wan't to filter the outbound mails so I can find out what is causing them to go to junk (I expect that even with the dedicated IP address and the reverse DNS entry some emails will still end up in junk. I don't expect 100% inbox rate but as far as I can reduce the junk rate withough significant financial impact, it's a win).
Also setting up PMG is very simple for me since I am already using PVE and thus I can just deploy a CT with the PMG in it.

It is not because GSuite's IP being blacklisted that your outgoing emails is being marked as junk? If that is the case then it is Google's responsibility to fix/prevent the issue happen in the first place.
 
It is not because GSuite's IP being blacklisted that your outgoing emails is being marked as junk? If that is the case then it is Google's responsibility to fix/prevent the issue happen in the first place.

Well that's one aspect of the issue but I think the users are at blame at some instances. Google is google, I do not think you can force them to do anything. As stated previously, they try to unlist the IPs and rotate them but this is not enough for us. But we want to use g suite services and the gmail web interface for the email is also liked by our users. So this seems the best aproach for now. I don't see us using another email provider for the forseable future. So we have to work with what we have. Good luck convinsing google to change their ways :)
What would be nice would be if the would have the option of a dedicated IP address or a pool of them.

Anyway. It is what it is. Can't do much about it. Thank you for your input.