Ex keeps emailing me after breakup – would reporting him be reasonable?

Hi everyone, I hope you’re doing well. I’m looking for some advice about ongoing contact from an ex.

I (25/F) ended a relationship about 4 months ago with my ex (25/M). During our relationship, he started treating me badly emotionally. After the breakup, he kept insisting that we get back together, alternating between messages of love and very aggressive messages. On several occasions, he said he would kill himself if we didn’t get back together. I blocked him, but since then he has sent me over 100 emails. In these messages, he would go from saying “you’re the love of my life, please let’s get back together” to saying “you’re a whore, you ruined my life.” Recently, a friend spoke with his siblings, and since then he has stopped contacting me, but I’m not sure if the situation is truly resolved or if he might try again.

Several people have told me that I should consider reporting him, but I don’t know what to do. Given this pattern of behavior, would reporting him be reasonable, or would that be considered an overreaction?