If you receive an e-mail from the sender “helpdesk” under your own e-mail domain, you should be careful. If this email then also contains the claim “Password for (…) expire today”, then a criminal is trying to get hold of the access data to your email address.
These are worth a lot of money. Because spam e-mails are sent via your e-mail address if you click on “Keep Same Password” and enter your data there.
Please note that new variants of this scam are constantly appearing. Never pass on the access data to your e-mail account to third parties!