Url duplicated in account activation link?

[SoTrue]

Hi all, I;m trying to bring quite a messy site up to scratch and am testing functionality as I go along.

I have just registered as a new user and received an email activation link, however the link has come in the format of:

https://www.mywebsite.comhttps://www.mywebsite.com/login/registration/activate?token=a7dd37e4be447ff25f68dc38abf0d2d6

The main url is duplicated. Even after correcting the url by removing the first part the page does not load. So basically I'm trying to figure out:

1 - How to correct the URL
2 - Why the generated token page reports the following error:

This site can't be reached

https's server DNS address could not be found.
Search Google for https pretty tomboy nation login registration activate
ERR_NAME_NOT_RESOLVED

I am using Joomla 3.6.5 with VM3.2.0

Any help or advice would be most welcome.
Regards
Donna

[jenkinhill]

The activation link is sent by Joomla, and should be of the format yourdomain.com/index.php?option=com_users&task=registration.activate&token=#############

Is there some extension installed to modify the registration process/email as you url is obviously different.

[SoTrue]

I am using Joomsef, I;m just checking the settings in there...thank you. I'll post back with my findings.
Regards
Donna