No, that is not normal. Definitely investigate that. However, if you are using Gmail (as your email provider) and you disabled "Less Secure App Access" then you will periodicly receive emails about abnormal activities which is actually normal (just K9 fetching your emails).
Re-enabling Secure Access will deny K9-Mail from being able to fetch your emails. -- You received this message because you are subscribed to the Google Groups "K-9 Mail" group. To unsubscribe from this group and stop receiving emails from it, send an email to k-9-mail+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/k-9-mail/620c8e84-eff7-4b95-9c69-7c39a6c40436%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
