I purchased this to use for their transactional email service, and discovered they are adding an automatic unsubscribe link (via a List-Unsubscribe header) to their transactional emails! This makes their transactional email service completely unusable, because you can't have customers unsubscribing from those (e.g. order confirmations, invoices, password resets, etc.).

When I asked about how to disable this, I got this response from their customer support: "Also, I would like to add, on shared IP sending, there is no possibility of removing the unsubcribe link, this is something we don't allow sadly," but "We might have some options if, the sending is done on dedicated IP [starts at $251 a year] and also, includes restriction of sending content." Nowhere is this mentioned in Sendinblue docs (only this: https://help.sendinblue.com/hc/en-us/articles/209502605-Manage-your-transactional-email-unsubscriptions -- implying the opposite; that unsubscribing from transactional emails has to be enabled if you want it.

I feel really misled by this. Even worse, emails to certain email service providers that have no deliverability issues when I switch to my other transactional email service are being blocked (not arriving at all) or going to spam when I use Sendinblue. I also reached out to customer support about this, and received the completely unhelpful response that "To fix this emails ending in SPAM, could you please ensure the contacts have added your sender email as a contact on their email client." ...That is their solution? Yikes.