Please be aware that in the most recent WordPress 4.3 update, WordPress changed core functionality relating to the generation of passwords. This means that OptimizeMember (or any plugin) is no longer able to send raw passwords via email.
We have now released OptimizeMember version 1.2.1 which helps resolve this issue
Please update your site to version 1.2.1 of OptimizeMember first then continue reading this article....
Using Customised New User Emails in 1.2.1 and above
If you are using the option to customize new user notification emails in OptimizeMember (found within OptimizeMember > General Options > Email Configuration > New User Email Configuration - "Yes")
You will now want to ensure you have modified your new user email to deal with the fact that passwords are no longer sent in emails
Plase replace any use of the %%user_pass%% replacement code with %%wp_set_pass_url%%
This will send a password reset link which allows the user to securely set a password for your site or have one generated by WordPress
You might also want to use some wording like this:
To set your password, click this link: %%wp_set_pass_url%%
Here's an example of how this section might look now:
Allowing Users to Choose Password at Signup
If you prefer for your users to enter their own password as part of the registration process, you can use the options within OptimizeMember > General Options > Registration/Profile Fields & Options > Allow Custom Passwords During Registration? - and set this to "Yes (allow members to create their own password during registration)
This setting will show password fields on the registration form that your member will see after completing the purchase. From here your user can create a password, and then confirm this password, and the password will be set for them
Please note that if you use this setting, the user will NOT be sent any logins via email for security as WordPress will not send a confirmation of the password.