Open chris001 opened 1 year ago
jcameron
commented
1 year ago That's not a bad idea - email deliverability is a real issue for people running small sites. Sadly I've seen cases where ever when all those requirements are met, some recipients still reject email for unknown reasons (ie. iCloud).
Other than RBLs, is there a better service to check for deliverability?
chris001
commented
1 year ago It doesn’t take into consideration as many factors as other tools do, but it looks into the most important ones.
You type your email domain or IP address on the homepage. Then you’ll be asked to provide basic information, your full name, work email, monthly volume, and country.
Once you hit the ‘What’s my score’ button, you’ll see information about DNS records, SSL certs, and the list of sending IPs with their respective sender scores.
A score of 80 or more is considered good. If you’re below 80, there’s room for improvement. You’ll notice a drop in your delivery rates when your score reduces even slightly.
If you register, you’ll see the ratings from the IP addresses you use for sending, as well as for related domains (domains sending email from, or web hosted on, the same IP as yours?). This score is one of the key things spam filters take into consideration when assessing whether an email should be delivered into the destination user's Inbox, or redirected into their Junk/Spam box.
Sender Score doesn’t give you any tips on how to improve the score and it’s also far from trivial. It sometimes takes years to build up a good Sender Score from scratch. Of course, when sending via an external email sender service, you use their domain rating, not yours, at the huge sacrifice of your users' privacy and making your organization's security vulnerable to spies and unknown malicious parties. Which is unacceptable for most informed and conscientious individual users and organizations.
‘Good’ indicates that the harmful behavior associated with this address is negligible at most. ‘Neutral’ means that you are still on a reasonable level but some messages may be filtered out. ‘Poor’ represents poor deliverability and probable issues with inbox placement.
Talos also gives insights into the spam level associated with your IP address, its presence on blacklists, and its email volume.
Note: If you’re mainly using subdomains to send emails, typing in the domain name may return limited results. Try searching for each subdomain to get accurate info.
SNDS is does more than monitor domain email sender reputation. It helps IP address owners (web and mail server admins) to detect compromised servers, malware, viruses, and botnets. SNDS helps network administrators detect these problems so that they can clean them up and make the internet a safer place.
To use Postmaster Tools, you’ll need to have a high sending volume. You’ll also need to add custom records to your DNS to get started. Then you’ll be able to see how your IP and domain reputations fluctuate on a 4-level scale (bad, low, medium/fair, high).
Google will also let you know how you’re doing in terms of authentication, spam reports, delivery errors, and encryption.
When you register, you’ll be assigned an individual email address that you can send emails to. It’s not tied to the address you signed up with. Your organization can start sending emails to it right away.
When you craft an email and send it to that assigned unique analysis email address, the site will then assess different aspects of your email message, and give you a score for each aspect.
SendForensics compares your results with those of thousands of other companies using their service. It then tells you where you rank and in which fields you should improve.
There’s additional data in the paid plans. A detailed analysis of content, with suggestions of words to use. Deeper insights into reputation, inbox placement and an option to preview emails for popular email apps.
Send Forensics can be connected with Google Postmaster and Microsoft SNDS tools.
In a few seconds after you send an email, you have a score ready. Mail-tester looks into various factors that affect deliverability. It checks the likelihood of it going to spam and gives tips on what to improve. It analyzes your domain for authentication methods (SPF, DKIM, DMARC) and reads the HTML code of your message, looking for things to improve. Finally, it checks if your domain made it to some blacklist recently which might affect your odds.
Spamcheck you paste your email’s full headers and full contents into the dialog box. You’ll get back a score in seconds; the lower, the better. And you will get comments about how to improve the email, addressing:
The quality of links in the content
Authentications of the sender domain
Text to image ratio (certain proportions trigger spam filters)
The general quality of HTML Like Mail-Tester, Spam Check uses the popular SpamAssassin to provide its assessment, so it’s reliable.
Postmark also allows you to integrate Spamcheck into your app and automatically run spam checks on all outgoing emails. For this purpose, they offer their API for free (even if you don’t use Postmark service to send your emails). Libraries for integrating with Perl, Python, and others are available.
GlockApps emulates email-sending through Postfix and two other platforms for sending emails. It then estimates where your email would land. You'll see, spam is not the only potential problem. A seemingly well-written and formatted email would skip most of the inboxes if sent with Mailgun! Lots of Gmail users would probably miss it too, because it would get buried under "other promotions".
The power of GlockApps is buried in the full reports available after registering (only the first three are free). Follow the instructions on the screen to send your test email to a carefully crafted list of recipients.
In a few seconds you should see your report.
You see lots of stats, same as from other tools. Since you sent an email to dozens of different domains spread between countries, you can also see how each performed. It’s useful when you know which accounts the majority of your contacts use. You can then predict how their mail app will react when exactly this message arrives, this time to a real inbox.
All you need to do is send your test email message to ping@tools.mxtoolbox.com - in a few minutes, you’ll receive an email back, with a link to your deliverability report. In this, you'll see if your domain has the essential authentications, and if they’re configured properly.
The Basics, without which, reliable deliverability is difficult
Proper authentication protocols will prove to all the incoming SMTP servers on the internet, that you, the sender, are who you say you are, the genuine sender, authorized to send on that domain and IP address, and with that TLS cert. In other words – you make it very hard for spammers or phishers to get away with impersonating you, and send malicious emails, as if they were from you, resulting in huge damage to your virtualmin mail server's sender reputation.
The standard set of authentications is
(1) SPF,
(2) DKIM, and
(3) the powerful DMARC.
Plus, it's essential for your SMTP MTA's (Postfix) MX record also have:
(4) PTR record(s) which resolve to your mailserver's hostname as it shows in its EHLO/HELO greeting banner, to other mail servers. Spam filters check if the SMTP banner greeting hostname matches your mail server IP's PTR record hostname, and deduct many points when mismatched!
(5) The hostname from your email server IP's PTR record must match to one of the hostnames in the TLS cert your SMTP server uses during SNI negotiation and STARTTLS or SSL encryption.
(6) Enabling TLS/SSL encryption on all SMTP traffic helps, and
(7) DNSSEC, TLSA and DANE, powerfully protect your sender score. These prevent scammers from performing a cache poisoning attack against a vulnerable remote caching DNS server administered by an ISP, which the spammer then uses to impersonate your highly trusted email sending domain, to send victims fully authenticated email messages containing spam malware and phishing attack emails, to all customers of that ISP, causing data losses, data theft, downtime, reports to RBLs, and ruin your clean sender score that took you many many hours of work to build up.
It's simple and dependable to utilize external outgoing email forwarders such as gmail or mailgun.
However, for a
virtualminserver to give all of its emails to an outside party ("Man In The Middle"), those external companies will mine data from the contents of the emails, and do anything with your data to make a profit. That sacrifices privacy, which is unacceptable for mostvirtualminusers and organizations, and should be for thevirtualminorg.virtualmin-gplsoftware could, and should, be made equally as strong on outgoing email as google gmail, mailgun, etc, in its outgoing email, try harder to be sure it will deliver messages reliably into the receiver's inbox, resilient against blacklisting on RBL denylists.External forwarders such as mailgun should be a distant third place fallback sending method, in case of emergency, when
virtualmindetects a bounce, and the email message is urgent priority, and when the email messages contain no personal or private information e.g. auth codes, password reset URLs, etc.There should be a feature "
Diagnostic Check - Outbound Email" to periodically auto check the outbound email server for best practice configuration which maximizes the resilience against IP blacklist:virtualminserver's domain's outgoing SMTP IPv4/IPv6 addresses, then send automated email message, every day, to those RBL denylist service admins, ask to remove thevirtualminserver's outgoing IP addresses from that RBL denylist, until the outgoing IP addresses are removed from RBL denylists.