When people try to respond to my emails there is a typo – it leaves out a letter. Very annoying as their replies to me keep bouncing back!

When I send an email to people and they hit the reply button they don't have to retype my email address - it goes there automatically. However the automatic address which appears has a typo in it (missing an r) so their emails bounce back repeatedly. I have had this address for about 10 years but this just started happening about 4 months ago. Very strange and I can't find a way to fix it!