Gmail: Top 5 Deliverability Do's and Don'ts

You can find an updated version here.


  1. Hi Al,

    Great read, thanks for the article.

    I have a few questions!

    "The only likely downside is that the encryption adds overhead to both the mail server software and the connections it makes to other servers. What that means is that mail can end up being delivered a bit more slowly with TLS enabled."

    I agree overhead is generated. Do you think additional server overhead is still applicable even in clustered environments? I haven't seen anyone create a bench mark for this metric. I'm just curious how much a factor it is.

    If an MTA server is experiencing performance issues post implementation, do you think this is due to poor infrastructure, an already existing performance issue, or an already needed hardware/resources upgrade?

    Do you think this is more OR less applicable in enterprise environments (millions of emails per hour)?
    "... and the connections it makes to other servers".

    Have you heard of any ISPs having handshaking issues upon accepting TLS? If so, is this more on the EPS or ISP' end? Any additional info would be great.

    Does TLS encryption increase the size of the email being transmitted. If so, is the size increase even noticeable in terms of server resources? Assuming best practices for creative/HTML are being utilized.

    Scenario: You're explaining TLS to a non tech savvy group and the goal is to implement encryption.You touch on all of the benefits and reasons why it's important to adopt this industry standard. Do you mention the 'take aways' of utilizing TLS (overhead/additional handshake)? By the way, compared to other teams, this specific one is easily overwhelmed by technical topics.


  2. Who in the hells checks the Promotions tab? I don't.

  3. I disabled it almost immediately in my account. I prefer more granular control of what goes where and have configured Gmail's filters accordingly.

  4. Hey Al,

    Thanks for sharing the knowledge.

    Any different recommendation when sending with an ESP (Mailchimp)?


  5. If you're using an ESP, you need to rely on the ESP for help with some of these. Numbers 3, 4 and 5 are definitely still on you. Things like DKIM, SPF, and TLS, those are functions that your ESP would have to enable or help you enable. Not sure which of those your ESP may offer or how they handle them. You'll have to ask.

    I believe that ESP also mostly has a shared IP address environment. If you send more than 200,000/month, you send enough mail to build a sending reputation of your own, on its own, dedicated, IP address. If you share your sending IP address with other folks, the sending reputation is more blended and inbox placement is less under your control. That doesn't mean it's bad, it just has some limitations to be aware of. You might want to ask your ESP about that.

  6. Hi,

    I'm running different website on dedicate server/ip, and sending emailing from there,
    And today i'm facing couple of question that i hope you could help.
    Today my server is running on qmail, so doesn't allow me to set Dkim or Tls.
    When I asked to my host, he told my Dkim & Tls is good for big company to ensure no one sends a message pretending to be me,
    But this wouldn't in anyway increase delivery/inbox rate?

    What do you think about?
    As I'll need to pay someone to set all this I would need to get some return on investment.

    The second point is about domain/ip reputation.
    I just set postmaster tools, which report me a bad reputation despite cleaning the base for some time. By unregistering, hard-bounces, non-reactive mail, 5 consecutive soft-bounce.
    How and how long it would take increase reputation?


Comments policy: Al is always right. Kidding, mostly. Be polite, and you're welcome to join in, even if it's a differing viewpoint.