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Old 12-01-2019, 01:00 AM   #1
mfoley
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Most of the emails from my mail server are going into SPAM on gmail


This has been happening a lot lately. When I send an email to someone with a gmail account it invariably goes into their SPAM. I tried this with a never-used gmail account of mine, sending from my own mail server novatec-inc.com, and it too went into SPAM. The reason given by gmail was, "Why is this message in spam? It is similar to messages that were identified as spam in the past." To whose "past" are they referring? Certainly not mine as this is the first email I've sent to that gmail account. I've posted a 'Support' message from my gmail account asking what the problem might be, but I've received no answer, and don't expect to.

Does anyone have any idea what I could look for to figure out why gmail considers me to be a SPAMmer? I need to sort this out because email is how I communicate to everyone, family, friends and customers.
 
Old 12-01-2019, 01:12 AM   #2
scasey
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Things to look at:
Does your mail server have a reverse DNS (rDNS)?
Is your mail serverís IP address a dynamic IP?
Is your mail serverís IP listed in any RBLs?
Look at the headers of the email received at gmail ó are there any indications there of why it got marked as SPAM?
 
Old 12-01-2019, 03:43 AM   #3
ondoho
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In very crude layman terms - there's something like SSL certificates for mail (DKIM), and if your mail server doesn't have that, it's not "Trusted".
Adding to that a slight misconfiguration or unorthodox way of setting it all up, gmail will certainly see it as spam.
 
Old 12-03-2019, 12:51 AM   #4
mfoley
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Quote:
Originally Posted by scasey View Post
Things to look at:
Does your mail server have a reverse DNS (rDNS)?
Is your mail server’s IP address a dynamic IP?
Is your mail server’s IP listed in any RBLs?
Look at the headers of the email received at gmail — are there any indications there of why it got marked as SPAM?
I do not have a reverse DNS:
Code:
$ host novatec-inc.com
novatec-inc.com has address 184.57.60.212
novatec-inc.com mail is handled by 10 novatec-inc.com.

$ host 184.57.60.212
212.60.57.184.in-addr.arpa domain name pointer cpe-184-57-60-212.columbus.res.rr.com.
where rr.com is RoadRunner (part of Spectrum/Time-Warner) and is my ISP and one of the SMART_HOST mail servers.

The IP address is Dynamic.

I checked my IP at https://whatismyipaddress.com/blacklist-check. Yes, it is listed at 3 blacklists: dnsbl.spfbl.net, dnsbl.sorbs.net, dul.dnsbl.sorbs.net. I'll have to investigate that. Last time I checked it wasn't my IP per se, but one of the roadRunner mail relays. My server is pretty secure. I'm sure no one is using me as an open relay, although spammers could certainly spoof my address. I monitor the log file and have spamassassin which I train regularly.

I am using TLS, but the cert was from cacert.org, which may not be recognized, and is expired anyway.

I suppose I really need to look into getting a static IP.
Quote:
Originally Posted by ondoho View Post
In very crude layman terms - there's something like SSL certificates for mail (DKIM), and if your mail server doesn't have that, it's not "Trusted".
Adding to that a slight misconfiguration or unorthodox way of setting it all up, gmail will certainly see it as spam.
I do have DKIM set up. Sometimes it seems to validate, sometimes not. That's a separate question I've posted.

Last edited by mfoley; 12-03-2019 at 12:53 AM.
 
Old 12-03-2019, 12:56 AM   #5
scasey
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No rDNS
A dynamic IP
Listed in RBLs

Any one of these could (probably does) cause email to marked as SPAM.
On my server theyíd cause the mail to be rejected (BOUNCed)
 
Old 12-03-2019, 06:28 AM   #6
TenTenths
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Your IP shows up as "Residential" when checked against at least one IP lookup service.

Mail providers generally don't like "Residential" IPs sending directly in to their mail servers as this is a good indication that the mail is coming from a compromised home machine that's on a 'botnet.

Either route your mail via your ISP's mail server, or get a cheap VPS with a large hosting company and use that as your outbound mail relay.
 
Old Yesterday, 06:43 AM   #7
bradvan
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I've been pretty happy using dynamic ip updating through no-ip. I've never had a problem sending to gmail. I'm running my domain from a server in my home and my ISP routinely changes my dynamically assigned ip address. I have a daemon running on my server that reaches out to no-ip's servers and updates my dynamically assigned ip. They then change my domain ip to point to the new dynamically assigned ip. Been using for a few years with no complaints.
 
Old Yesterday, 06:48 AM   #8
TenTenths
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Quote:
Originally Posted by bradvan View Post
I've been pretty happy using dynamic ip updating through no-ip. I've never had a problem sending to gmail. I'm running my domain from a server in my home and my ISP routinely changes my dynamically assigned ip address. I have a daemon running on my server that reaches out to no-ip's servers and updates my dynamically assigned ip. They then change my domain ip to point to the new dynamically assigned ip. Been using for a few years with no complaints.
Lucky you! Depends on how your ISP address range is classified by sources such as MaxMind. I suppose if it's non-residential, or has a high "static IP score" then it may be acceptable
 
Old Yesterday, 03:01 PM   #9
scasey
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Quote:
Originally Posted by TenTenths View Post
Lucky you! Depends on how your ISP address range is classified by sources such as MaxMind. I suppose if it's non-residential, or has a high "static IP score" then it may be acceptable
no-ip is a "dynamic DNS" service that provides a static IP to domains and forwards requests to the ISPs dynamic IP. The user's dynamic IP is never seen.
 
Old Yesterday, 03:04 PM   #10
TenTenths
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Quote:
Originally Posted by scasey View Post
no-ip is a "dynamic DNS" service that provides a static IP to domains and forwards requests to the ISPs dynamic IP. The user's dynamic IP is never seen.
Ah, I learn something every day!
 
Old Today, 03:02 PM   #11
mfoley
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Quote:
Originally Posted by scasey View Post
No rDNS
A dynamic IP
Listed in RBLs

Any one of these could (probably does) cause email to marked as SPAM.
On my server they’d cause the mail to be rejected (BOUNCed)
Yes, that's what I'm thinking too. I've been using this setup for more than a decade w/o too much problem, but I guess email ISP's are getting more strict lately. It's getting to be a real problem.
Quote:
Originally Posted by TenTenths View Post
Your IP shows up as "Residential" when checked against at least one IP lookup service.

Mail providers generally don't like "Residential" IPs sending directly in to their mail servers as this is a good indication that the mail is coming from a compromised home machine that's on a 'botnet.

Either route your mail via your ISP's mail server, or get a cheap VPS with a large hosting company and use that as your outbound mail relay.
Actually, my mail is routed via the ISP mail server. My sendmail SMART_HOST is mail.twc.com, I'm using port 587 and I have the authinfo feature configured. I think the problem is that the domain itself is dynamic and there is no rDNS. The MX record points to my domain, whose IP is dynamic and, as you say, "Residential":
Code:
novatec-inc.com has address 184.57.60.212
novatec-inc.com mail is handled by 10 novatec-inc.com.
Quote:
Originally Posted by bradvan View Post
I've been pretty happy using dynamic ip updating through no-ip. I've never had a problem sending to gmail. I'm running my domain from a server in my home and my ISP routinely changes my dynamically assigned ip address. I have a daemon running on my server that reaches out to no-ip's servers and updates my dynamically assigned ip. They then change my domain ip to point to the new dynamically assigned ip. Been using for a few years with no complaints.
no-ip is intriguing. I've not heard of that before. What about your domain name? Is it also pointing to a dynamic IP like mine? Does no-ip handle that?

I'll investigate no-ip, but I do have access to a server with a static IP. I'll post that as a separate thread since this issue has been answered.
 
  


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