Gmail is the only reliable email sender on this planet

— Posted inUncategorized — 2 min read

If you need to send an important email, Gmail is the only reliable email sender on this planet. It’s not just Google’s technology that’s reliable; other email services automatically accept mail from Gmail. Any other email service, whether paid or free, might have issues when sending your important emails. Don’t believe me? Here are some personal examples.

Last night, I sent an important email to several business partners using Tutanota. Unfortunately, the email wasn’t delivered and was bounced back. Here’s a screenshot of the bounce message. When I switched to Gmail, the email was sent successfully.

If you use iCloud Mail, sending emails is even less reliable. Your email might be silently discarded. Here’s an example from my experience.

People say Fastmail is great, but Pobox, which is owned by Fastmail, also has sending issues. For instance, one of my emails was rejected because the header contained “php-mailer,” and my account was suspended. Here’s the customer service response.

I reviewed the reason for you receiving this mail and it appears that Vade marked this as spam due to the X-mailer-sender that you used: X-Mailer: PHPMailer 6.5.1

The well-known GMX/Web.de also has problems. If you use their email service to send mail from an IP address outside Europe, your message goes through a separate gateway with a spam-listed IP address. As a result, the recipient may not receive your email or it might end up in their spam folder. Here’s a relevant forum post.

Outlook has the same issue as iCloud, with silent filtering, and it might even be worse. Don’t take my word for it; search for online posts about this.

I’m not sure about Yahoo’s current status, as I haven’t used it in a long time. Previously, emails sent from Yahoo servers experienced severe delays, which essentially made the service unreliable.

In conclusion, if you’re sending important emails, just stick with Gmail. Thinking about this, I went ahead and registered dozens of Gmail addresses as backups.

How to remove client sender IP from postfix

— Posted inUncategorized — 2 min read

There may have different methods to implement this feature. But I use the way from answer from serverfault.

First, I have to install postfix-pcre in my debian/ubuntu system,

sudo apt install postfix-pcre

Then, I defined a cleanup service in master.cf,

ascleanup   unix  n       -       y       -       0       cleanup
  -o header_checks=pcre:/etc/postfix/header_checks_submission

Let’s update submission and smtps in master.cf to use this cleanup service,

submission inet n       -       y       -       -       smtpd
  -o smtpd_sasl_auth_enable=yes
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_tls_auth_only=yes
  -o smtpd_reject_unlisted_recipient=no
  -o smtpd_recipient_restrictions=
  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
  -o cleanup_service_name=ascleanup

smtps     inet  n       -       y       -       -       smtpd
  -o syslog_name=postfix/smtps
  -o smtpd_tls_wrappermode=yes
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_reject_unlisted_recipient=no
  -o smtpd_recipient_restrictions=
  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
  -o cleanup_service_name=ascleanup

pickup    unix  n       -       y       60      1       pickup
cleanup   unix  n       -       y       -       0       cleanup
ascleanup   unix  n       -       y       -       0       cleanup
  -o header_checks=pcre:/etc/postfix/header_checks_submission

As you see above, ‘-o cleanup_service_name=ascleanup’ option was added into submission and smtps services.

The last, here is the content in /etc/postfix/header_checks_submission,

/^Received: .*/ IGNORE

Now, restart postfix and new configuration should be working. When you send a message from client via smtps/submission, you will see that client’s IP is removed from the headers.

A meaningful email domain is better than a generic domain

— Posted inUncategorized — 2 min read

When selecting an email domain, a meaningful name carries more weight than a generic one. Take aol.com, for instance, which stands for America Online – it’s a solid choice for email addresses because it’s easy to remember. In contrast, web.com falls short. While it might look good on paper, its meaning is too broad and lacks specific value.

Let’s compare gmail.com and mail.com. Gmail, representing Google Mail, has become the internet’s top brand. Mail.com, a product of 1&1, has an excellent domain name but lacks distinct brand value.

Two other notable products from 1&1 are GMX and web.de. GMX is widely recognized in Europe (and has a global presence), standing for Global Mail eXchange. Web.de, however, lacks unique brand appeal and is primarily used within Germany, making it less renowned than GMX.

Yandex, a Russian search engine company, has a well-known email service with users worldwide. Generally, those who trust Yandex’s search engine also favor its email offering. In contrast, mail.ru, another Russian email provider, is mostly recognized only within Russia.

Inbox.com, a generic domain name belonging to an American email company, has a long history but hasn’t managed to make significant market inroads. Its lack of a distinctive meaning contributes to its lukewarm reception. On the flip side, inbox.lv, a Latvian email company, has gained considerable fame in Europe. Its other products include mail.ee and inbox.eu. In this case, the “lv” suffix, representing Latvia, arguably carries more weight than a generic “.com”.

How to reject a sender domain in postfix

— Posted inUncategorized — 1 min read

Though postfix is the most widely used MTA software on internet, it’s hard to find every detail for setup it correctly. For example, how to reject a sender domain in postfix? I took quite a few time to check the doc to get answers.

If the rejected domains list is short, it can go in main.cf:

smtpd_sender_restrictions = inline:{
  { example.com = reject }
  { other.example = reject} }

Otherwise some external file will do it as follows.

/etc/postfix/main.cf:

smtpd_sender_restrictions = hash:/etc/postfix/sender-access

/etc/postfix/sender-access:

example.com reject
other.example reject

Run “postmap /etc/postfix/sender-access” after editing the file.

If you have rspamd or spamassassin installed with postfix, it’s more easy to control rejected domains in them.

email addresses with nice domains

— Posted inUncategorized — 1 min read

Here is the list I gathered. These email providers are still active on internet. They have a simple domain, like mail.xx or inbox.xx, which are easy to remember. Hope you like it.