Sending a lot of email notifications?

Question

Email

There is some service. Users indicate their email during registration, receive a password to it. On the same email, they receive notifications about important events for them. The volume of letters is growing, in the near future 10-20 thousand messages per day are expected.

The question is the following. How to send letters correctly so that they are almost guaranteed to reach and not fall into spam? Directly from the IP address of the provider does not work: there is no address in the blacklists, but the provider's networks are entirely present in some gray lists, so the IP Reputation is rather poor and letters often end up in spam or are rejected altogether. What paid SMTP service would you recommend for sending such critical emails (let me remind you that you receive a password when registering by email)? Maybe there are services that provide a guaranteed white IP address via VPN? At the moment we are using SMTP mail.nic.ru and we are not satisfied with its work.

Answer 1

And there is no desire to put your smtp? Or are there any counter-indications for this?

Answer 2

Google has very specific requirements for mailings, I think the rest have the same
approximate mail.google.com/support/bin/answer.py?hl=en&answer=81126
It may not save you from the existing gray list, but at least you can not screw up the new IP :-)

Answer 3

There is nothing easier, just use postmarkapp.com

Answer 4

The problem is temporarily solved, even in SenderBase they raised their reputation :) DKIM for gmail is also configured. If someone else encounters a similar problem, write in a personal, I will share my experience :)

Answer 5

If you need a high-quality SMTP service, then in fact there are only two options: Mandrill and SendGrid .

Answer 6

MailChimp

Answer 7

Each ESP has its own spammer IP database.
First of all, problems arise when choosing to send mail to a server with an IP marked in these databases.
For example, we only send standard site notifications - registration, password reminder, etc.
Tried different smtp and services.
There were smtp which "loved" all known ESP. But such services are completely limited in the number of messages sent. At "rush hour" 17-21 Moscow time 90% returned with an error like "too many messages".
There were mail forwarding services with a good reputation. All ESPs accepted mail from him favorably. But as a rule, there was one ESP that marked mail from the IP service as "spam".
So you have to constantly monitor not only the reputation of your IP, but also the reputation of all IPs that are marked in the service part of your letters along the way to ESP.
Ideally, they shouldn't be. But to make from scratch a server for sending mail that will not fall into SPAM is a great success.
---
An important addition.
Continuing the investigation, we found out the following: one of the important indicators affecting reputation is the percentage of messages delivered. They must be at least 95%. If more than 5% of emails receive an error like "address does not exist" - this is considered one of the signs of spam mailings.
Services like mailgan.com have an API that checks the correctness of the address (checking takes no more than a second). And to save your reputation, it's important to use this validation of the e-mail address before sending.
I will say more - such services can send your letters through "spam-stained" IPs and some ESPs will throw your mail into spam. And you will not receive a new address until you cross the 5% threshold. As soon as the percentage of "rejection" becomes less than 5% (3-4%), you can contact the server's technical support with a complaint that your letters are going to spam...
Conclusion: for reliable delivery, you must use scripts for checking addresses entered by users. Or the reputation of your IP with ESP may fall over time.