Are there ways to prevent that or is the only option I have is to pay for the domain until I die?

Depending on who is hosting your email, you maybe able to setup an auto-responder.

Usually some kind of vacation responder is available. Either that or rule/filter can be the same thing.

If new email arrives reply "this account is no longer active please redirect your emails to ....." or "this is services is no longer available please discontinue sending emails"

Same thing with vacation responder.

https://tools.ietf.org/html/rfc1846

521 does not accept mail (see rfc1846)

I don't know if you can configure your mail server to do a 521 response or not.

Anyway after about a year of this everyone should get the idea and stop sending emails.

Are there ways to prevent that or is the only option I have is to pay for the domain until I die?

Depending on who is hosting your email, you maybe able to setup an auto-responder.

Usually some kind of vacation responder is available. Either that or rule/filter can be the same thing.

If new email arrives reply "this account is no longer active please redirect your emails to ....." or "this is services is no longer available please discontinue sending emails"

Same thing with vacation responder.

https://www.rfc-editor.org/rfc/rfc1846

521 does not accept mail (see rfc1846)

I don't know if you can configure your mail server to do a 521 response or not.

Anyway after about a year of this everyone should get the idea and stop sending emails.