I used SparkPost for a while, they regularly disabled my account for no reason. The first time it was because I migrated a site from a dev area to the live domain, and forgot to change the sending domain. For that "offense" they totally canceled my account, and banned my email address, with no way to get it back. The second time they never told my why they deleted my account (new email). The just... did. I never spam, my sites barely use email for anything other than user forms. Sparkpost is a terrible business, I highly recommend you find another service instead.

2 reports of emails not being sent by different clients this week. One ended up working by removing the Mark emails as transactional check mark, and the other one just won't work anymore. Looking for another service. Disappointed to see such a HUGE company not keep their plugins up to date.

SparkPost lets your website use their servers to send your website's transactional emails. They have outstanding logging and are the best solution I've found. This is one of the first plugins I install on EVERY site I work with. Outstanding!

Plugin works well. Doesn't slow anything down. I get an error related to the debugging though: WordPress database error Too many keys specified; max 64 keys allowed for query ALTER TABLE sp_email_logs

It added +5 seconds on checkout and wherever emails were sent.

As leofflerg points out you can't trust them not to suspend you without warning. One of our client's account was suspended because someone sent a spam link to them using their site's contact form. The client tried contacting their compliance team, not really being very technically savvy, they didn't understand where the spam they were being blamed for came from. After all they didn't send the spam. As an agency manager, I reached out to Sparkpost's compliance once my client notified me of the situation. I just got an automated response saying Hello, Thank you for your interest in SparkPost. We strive to offer the very best email service, and to that end, we maintain a strict anti-abuse messaging policy. Because we cannot offer you the high deliverability you would expect from SparkPost, we must decline to provide our services. We wish you the best in your future business endeavors. Respectfully, The SparkPost Compliance Team So then I tried the head of business development, Beverly Clarke. She connected me with the account manager, Tim Tran. Who politely informed me I have taken a look at [redacted] and overall looks fine to me. I would continue to try to communicate with our Compliance team and follow their guidance. It would help to figure out how to prevent these links from appearing in your emails or how your system handles outbound email. I told him about the non-response we were getting from compliance, to which he replied... I don't see terminated on your account just yet. But if that's the only response they're giving you, we regretfully have to part ways at this point. It's some perverse form of digital victim blaming. My client was the victim of contact form spam, and Sparkpost is punishing them for not having done a good enough job of protecting themselves. It doesn't seem to matter at all to Sparkpost that the client didn't send the spam or that the recipient of the email was the party they were blaming for sending. I feel like I have egg on my face for recommending SparkPost to my clients after today. I can't in good conscious recommend anyone use their service and by proxy this plugin.