What are the advantages of using an external email sending provider?

Assuming I send 10k emails daily, does it make sense to switch to an external provider such as Sendgrid / Postmark / Amazon SES? Why?

Is it because of my customers having a better chance of receiving the emails (ie. their servers have better reputation, they know better how to deal with SPF / DKIM / etc.)?

Is it because I don't need to worry about the configuration / administration of the SMTP server?

Is it because of bandwidth or server load?

Is it because of better dealing with unsubscriptions / bounces / etc?

Is it all of the above? :)

I'm asking because I have a system that works. It's not 100% reliable (still some mails getting lost on the way) and I'm sure it could be improved in other ways too - but I want to know what benefits I could expect from switching to an external provider.

PS: I'm definitely not a spammer. I'm sending some information people have asked for. :)

All of the above!

• Do you want to spend your time fussing over your SMTP server?
• Do you want to always ensure that your SPF records and DKIM is correct?
• Do you want to spend a lot of time building your own methods of checking for delivers, - bounces, opens, and clicks?
• Do you want to spend a lot of time checking on the reputation of your IP address and making sure that it is whitelisted?
• Do you want to spend a lot of time flattening your HTML and CSS for your templates?

If you answered yes to any of these, then maybe not. Otherwise, the nominal fee you would pay for an external service is well worth having a lot more time to focus on your product rather than having to spend even a minute on your emails.

I'm the Product Manager for PostageApp, an outbound transactional email provider that makes it super easy to design, send, and manage those emails, so if you have any questions about our industry or our product specifically, feel free to ask!

I'd say all things you mentioned are correct. But if you're trying to justify financially...

Postmark = $15/10K emails

So you would spend $450/mo. I think if you spend more than 5 hours a month it is a no-brainer to offload it so your time can be spent on creating value in your business instead of admin.

If finance is not a concern, then the one thing you're probably missing is the level of expertise that a company like sendgrid and postmark have. I like to think if there are whole businesses dedicated to something, I shouldn't think I can do as good of a job of it by spending a few hours here and there. I think email delivery is extremely nuanced and takes a lot of maintenance and babysitting.