how do you title a resigning email?

[SeptemberSky]

Hi. My friend is going to send an email to his client telling them that he is resigning the company. In this case, what would you write as the subject of the email?
Could it be "resignation notice," "resignation letter," "April 5 will be my last day" or what do you usually say?

[Casiopea]

All of those are fine. There's also, My resignation.

[queenbu]

Hi. My friend is going to send an email to his client telling them that he is resigning from the company. In this case, what would you write as the subject of the email?
Could it be "resignation notice," "resignation letter," "April 5 will be my last day" or what do you usually say?

btw I don't really like 'April 5 will be my last day' as the subject.

[SeptemberSky]

Thank you, teachers!

[Casiopea]

You're welcome.