Tell HN: Gmail rate limiting emails from AWS SES

67 points by saradhi 2 years ago | 87 comments

Unsure if this is the same for everyone but our notification emails from SES are being rate limited by Gmail.

Background:

One of my apps provides time-sensitive email notifications, for 60-90 days, to the subscribers(paid) - so it is critical to deliver emails. We have been using the same email provider and have been using AWS SES for a couple of years now. We have the SPF, and DKIM all verified. Yet, for the last 3 days, we are getting the below email

```

Sub: Delivery Status Notification (Failure)

Body: Our system has detected an unusual rate of<CRLF>421-4.7.28 unsolicited mail originating from your IP address. To protect our<CRLF>421-4.7.28 users from spam, mail sent from your IP address has been temporarily<CRLF>421-4.7.28 rate limited. Please visit<CRLF>421-4.7.28 https://support.google.com/mail/?p=UnsolicitedRateLimitError to<CRLF>421 4.7.28 review our Bulk Email Senders Guidelines.>

```

Troubleshooting till now: I have got the AWS tech support team confirming my email configuration has no issues. AWS team has informed "The current throttling is just that Gmail is seeing a lot of messages from the SES shared IP and is throttling the messages"

>>> Is anyone facing the same issue with AWS? or similar issues with other bulk email service providers?

>>> How do you deal with such issues in the future? Set up alternative email service providers.

>>> Is this the side effect of Gmail's dormant account deletion rolled out last week?

jeroenhd 2 years ago |

Things like this are to be expected with shared IP addresses for mail services.

This sounds like something Amazon should figure out more than anything. There's probably something going on with a customer or theirs (misconfiguration, spammer, vulnerability exploited) that's triggering spam detection rules.

At least Google reports the issue back to you instead of silently dropping all of your email like many other mail servers do.

nomilk 2 years ago | |

Very useful thread. I recently considered SES for a quick app and didn't discover the purpose of dedicated IPs. They're listed under add ons, but seem somewhat essential if the emails are important.

Checking out the pricing page, a dedicated IP costs $24.95 per month, which would be more than the actual cost of emails for many small-medium apps (e.g. 100K emails per month would be about $10).

Ooc, do other email providers have the same shared-IP problem? E.g. Mailgun, Postmark, Sendgrid?

Source: https://aws.amazon.com/ses/pricing/

LinuxBender 2 years ago | | |

do other email providers have the same shared-IP problem?

Yes, that is why they let people get a dedicated IP pools and FCrDNS using their corporation name for a price. It is not uncommon for the shared IP pools to get rate limits, temporary blocks, etc... and the corporation specific dedicated IP's are more likely to get through especially if they handle UCE complaints properly.

dubcanada 2 years ago | | |

Postmark spends A LOT of effort to keep their shared IPs perfect. Rather complex setup with verification. And lots of stuff in place to prevent anything spam related.

But everyone else doesn't really care much.

shmoogy 2 years ago | | |

Dedicated can be an issue unless you have sufficient volume, unless I've been mislead in the past.

bdcravens 2 years ago | | |

Sendgrid's cheapest plan with a dedicated IP is $89/mo.

alyandon 2 years ago | |

I finally started sending anything from AWS SES straight to trash because the spam on their platform is persistent and they are non-responsive to spam reports. I was getting 30+ fraudulent/spam emails a day in just one inbox alone.

nostrebored 2 years ago | | |

That's untrue. I can tell you that spam reports and bounces are monitored, and customers do have to go through validation of their workflows if they breach thresholds.

I had to help multiple customers who had access to SES shut off for valid use cases because they didn't handle events coming back from customers appropriately.

moltar 2 years ago | | |

Not sure if this is an edge case or not. But getting approved for SES isn’t that simple. And then shut downs happen very quickly even for legitimate cases. AWS is very aggressive with SES.

baobabKoodaa 2 years ago | |

Google also silently drops mail in some cases.

jeroenhd 2 years ago | | |

I've never experienced that. When mail gets dropped, my experience is that you either receive a notice from the SMTP service or get a DMARC report that tells you about the percentage of dropped mail.

jeffbee 2 years ago | | |

Which cases?

pembrook 2 years ago |

Email sending is a largely efficient market, and SES is the cheapest sender.

Thus, the SES IP pools have the worst IP reputations among all the SMTP-based senders. I would never use them (or an ESP that sends with them) in a million years.

The reason why cheap = bad in email is because Spammers have the lowest conversion rates of all senders (their emails are always untargeted), so price is their number 1 consideration.

You can cheap out elsewhere in your stack. But never cheap out on email — especially if you’re not sending high volume enough for a dedicated IP.

slau 2 years ago |

It sounds like you could benefit from having your own dedicated IP pool in SES.

https://docs.aws.amazon.com/ses/latest/dg/dedicated-ip.html

kunwon1 2 years ago |

Amazon SES is not a good choice for sending critical email notifications. Their 'global suppression list' [1] has caused no end of headaches for me and my clients.

If you and I are both using SES to send to the same person, and my message results in a hard bounce, then your messages to that person will start to silently fail.

[1] https://docs.aws.amazon.com/ses/latest/dg/sending-email-glob...

johanneswu 2 years ago | |

You can now use a account-level suppression list to override the global suppression list though.

> If an address is on the global suppression list, but not on your account level suppression list (which means you want to send to it), and you do send to it, Amazon SES will still attempt delivery, but if it bounces, the bounce will affect your own reputation

[1] https://docs.aws.amazon.com/ses/latest/dg/lists-and-subscrip...

kunwon1 2 years ago | | |

Interesting. I've worked with vendors (Including VMWare/Carbon Black) that told me they couldn't override the global list. Maybe the product is evolving to address these (past?) flaws

messutied 2 years ago | |

Would you happen to know of better alternatives for sending critical email notifications? We're just now working on moving away from Mailgun into SES. This thread is making me reconsider.

mprovost 2 years ago | | |

"Critical" and "email" don't generally go together.

kunwon1 2 years ago | | |

To echo the other reply, I don't rely on email for critical comms.

If I had to rely on email for critical comms, I would use a product that lets me see the SMTP logs, and alert on failures. I would have some backup provider that I could then quickly shift to

But I'm still an on-prem email administrator, so my entire paradigm is pretty much obsolete. I may not be the best source of info in this space

saradhi 2 years ago |

Thanks you all for comments. I have made a decision to subscribed to dedicated IPs (credits: @slau).

The differentiating factor between our current AWS SES plan and the competitors (mentioned in the comments) is having a dedicated IP. With our current volume, none of the competitors are anyway near AWS SES costs. So, moving to a dedicated IPs thats cost 25$ extra not only solves our issue, but also no change in code/infrastructure.

slau 2 years ago | |

Just make sure you have sufficient traffic to warrant a dedicated IP. An unknown IP suddenly sending a burst of emails is going to get soft-blocked very quickly. You need to build up your reputation, and you need to slowly increase how much you send.

The managed IP is an option, although I’ve never used it.

When I was the VPoE at Dixa, we switched over to SES, and we had 3 dedicated IPs, and for our volume back then (a few thousand emails a day), this worked very well. I don’t know if they ever hit scaling issues after I left.

ttul 2 years ago |

Hey everyone, CEO of MailChannels here. I've been following this thread with interest, as we've also observed similar challenges in the email delivery space. Well, to be honest, the ground game is constantly changing in this space as everyone has scaled.

Email delivery is inherently complex due to the various factors that contribute to deliverability, including IP reputation, domain reputation, content filtering, and recipient engagement. Shared IP pools can indeed be challenging because of the "bad neighbor" effect, where one sender's bad behavior can affect the reputation of all senders using that IP.

However, shared pools can also prove advantageous because it's harder for a receiver to block your IP if tons of email comes from it from a wide variety of senders. Receivers are trying to reduce collateral damage while protecting their users from spam and phishing - this is literally the reward model feeding their machine learning models. If your email travels alongside millions of other emails that are mostly received well, that IP will not be blocked; whereas, if you send email from your own IP, it doesn't take much for a receiver to pull the trigger and block you since there is very little consequence other than blocking your traffic.

Not that anyone here asked, but if you want a "best practice", try multiple different services and approaches and find the one that works best for you. There is no perfect email sending service for all senders and as mentioned above, the ground game is changing all the time.

LeonM 2 years ago |

This is typically not a big deal, as explained in the message, it is a temporary countermeasure. It'll resolve itself as long as you really aren't spamming.

Though Gmail responds citing your IP, Gmail and all other large email services don't use IP filtering. Just about all email service providers use domain reputation, since IPs are ephemeral.

If you are sending transactional emails that your customers have agreed to, then your domain (!= ip) rating will improve over time and there will be less countermeasures, regardless of which IP you use to send.

> Is anyone facing the same issue with AWS? or similar issues with other bulk email service providers?

This is just Gmail doing it's thing (the right thing, in my opinion, contrary to most HN sentiment). It is independent of which sender you use.

> How do you deal with such issues in the future? Set up alternative email service providers.

Use DMARC reporting to verify that all your email is sent with DKIM alignment, to make sure that you aren't causing the problem. This is independent of email service provider.

But as explained, you are being rate limited, not blocked. Email will be delivered, it'll just take longer. You state that you have a 60-90 day margin for delivery, so I wouldn't worry about it too much.

> Is this the side effect of Gmail's dormant account deletion rolled out last week?

No.

leetrout 2 years ago | |

Not entirely true. There is a reason Mailchimp owns a rather large block of IP addresses.

https://ipinfo.io/AS14782

LeonM 2 years ago | | |

> Not entirely true

OK you are right, Gmail may use IP-based rating, but it only does that if there isn't sufficient proof (in form of DKIM signatures) that the email is sent on behalf of the domain. If the email is DKIM aligned, then domain rating is used. I just didn't want to go that far into detail in my post.

> There is a reason Mailchimp owns a rather large block of IP addresses.

The reason is mostly for supporting smaller/legacy/self-hosted email services that do rely on IP reputation. Since Mailchimp won't allow customers to bulk email unless they have DKIM set up correctly, they don't have to worry as much about IP spreading with the major email service providers.

joshstrange 2 years ago |

I'm currently using PostmarkApp (from before the acquisition) but I've looked longingly at SES for years. My traffic is very bursty and so ~8 months out of the year I pay the monthly cost and send 1-2 emails if that and then the other 3 months I send close to my plan max. I'd love to switch to a pay-per-use provider but stories like this scare me. I've already dealt with deliverability issues (iCloud randomly deciding that unless you can receive emails, have the MX records in place, they will block you. This was for transactional/login/notification emails), since email is the login method for my sites it's rather important that it works. To PostmarkApp's credit they helped me to track down why the emails were bouncing to iCloud, I doubt I would have gotten the same support from AWS (I'm too small of a fish).

I'd love to hear what other people are using to send transactional emails (no marketing). Ideally I'd find a provider that could "scale down to $0".

baobabKoodaa 2 years ago |

If you are not in the business of selling email delivery, you should be buying email delivery from a company who is in that business. It's extremely hard to get emails delivered and it's even harder for a small company. For your use case you could probably use Postmark and get good delivery with that.

topicseed 2 years ago |

I think this is a spammy neighbour problem on that sending IP. Might be you, might be someone else who's using SES. But whoever sends from this IP is penalised.

ctas 2 years ago |

Do you have a custom return-path configured? Using a custom return path might help, because it ties your reputation primarily to your domain.

ESPs check multiple factors. Both IP and domain reputation play a role. They will check your return path / envelope sender domain reputation and your IP. Your domain will start with it's own reputation, but can be boosted with a good IP reputation. But if your domain had bad sending behaviour in the past, that might be an issue.

Source: I'm running a transactional mail service that solely works with shared IPs: https://www.markix.com.

cuu508 2 years ago | |

FYI: Your privacy policy is missing https://app.markix.com/privacy-policy

johnklos 2 years ago |

Amazon is very, very spammy. If you want your email to be delivered and you don't want to end up sharing Amazon's reputation, you'll need to use another company for email delivery.

vladvasiliu 2 years ago |

>>> Is this the side effect of Gmail's dormant account deletion rolled out last week?

IIRC, they haven't started to actually close the accounts just yet, so I doubt it's related.

bdcravens 2 years ago |

We are always trying to trim waste to stay lean, and the SES vs Sendgrid pricing looks nice on paper (we are on the Sendgrid Pro plan with the dedicated IP address, so it's $90/mo). However when I look at our Sendgrid stats (97% reputation; it's pretty much all transactional) I know it's worth well more than what we'd save.

jeffbee 2 years ago |

Why does a 4xx even come to your attention? Admittedly I never looked into what SES is or how it works, but I assumed it stores and forwards messages on behalf of its users, in which case a 4xx temporary failure to send should not come back to you.

hstaab 2 years ago |

For those recommending against SES for critical deliveries, what are you using?

In the recent past I’ve used Postmark, but they were acquired by a marketing company.

erksa 2 years ago | |

For any critical email delivery make sure you can address this thing with the mailsender of choise:

1)SPF,

2)DKIM,

3)DMARC [2] (DMARC is often forgotten or can be super noisy when set up. Postmarc offers a aggregation service for free that sends you a weekly summary),

4)Dedicated IP

5)Reverse IP look up [1] (locate a dns PTR record for that IP address) should match the sender.

Not everyone supports 5).

4 and 5 is what you end up paying for, but totally worth it. Sendgrid, SES, Mailgun etc.

[1] https://www.mailgun.com/blog/deliverability/reverse-dns-whit...

[2] https://dmarc.postmarkapp.com/

joshstrange 2 years ago | | |

And 1 surprising thing (to me) is some places (iCloud was what bit me) alway want you to be able to receive email (have MX records). Even though I have no need to support incoming emails iCloud was blocking my sending until I got that setup. The incoming emails just go to a black hole but that's enough.

ctas 2 years ago | |

Shameless plug: I've recently started my own transactional email service (https://www.markix.com), primarily targeting small senders, after having been a very happy Postmark customer for a long time. Our service is still in closed beta but delivering live emails.

I run a couple other businesses and moved all of my transactional email sending over to Markix.

Would love to have a chat with anyone that might be starting a new project and is open to try out a new mail service (mail in bio).

the_common_man 2 years ago |

Funny because Gmail is the biggest source of spam

pixl97 2 years ago | |

Gmail is also one of the biggest email providers... it's almost like there is a correlation.

ds 2 years ago |

I tried to use cloudflare email routing and had the same issue. I simply set it up so any email to @mydomain.com would forward to a gmail.

The worst is that cloudflare did not let me know this was happening until I saw I was missing some emails and went hunting. About 20% of my emails would just get rejected silently with "delivery failed" in the logs. I wouldnt blame cloudflare so much if they kept attempting to redeliver, but they did not. They simply give up.