Mailbox providers evaluate you as a sender using metrics like: 🔸 Do people open your emails? 🔸 Do people engage with your email content? When people don't need to open your emails, they usually won't.

If you include OTP codes in the subject line, it may lead to lower engagement, and could impact your deliverability. For more tips, check out our deliverability guide:

Yeah, wish it wasn't this way, but it's understandable that mailbox providers need a signal that your emails are interesting to recipients. ☹️