Subscribe by email and mandrill.com sending

Hi there.

Please refer to my previous post regarding this.
https://premium.wpmudev.org/forums/topic/subscribe-by-email-with-double-spacings#post-772737

I have about 230 websites, mostly wordpress, different plugins, hesk.com, moodle and some other sites, now all connected to send mail through mandrill.com.

I really need to move this last site over also, but still seems to be getting issues with the subscribe by email plugin sending through mandrill.com.

Been testing with multiple email accounts. About 50% of the newsletters is correct and the other 50% 'seems to have" double spacing's between the lines. Seems to be a random issue.

None of the other plugins, sites or software we use seems to do this. Have other newsletter plugins and all the emails goes through correctly.

See attached .zip file - tried to save it as HTML to show.

Any suggestions?

EZ