Customers get an error message when trying to reset password

I updated my plugin and have since been getting complaints of members not able to reset their password due to the following message:

"The e-mail could not be sent.
Possible reason: your host may have disabled the mail() function."

I've not changed anything other than update the M2 plugin. I contacted my host provider to see if anything had changed but nothing has. Are you aware of this issue at all? Are you able to help?

Kind regards,

Ash