The evidence supplied in the tweet consists of two partial images, by clicking through you can see the complete images, here they are, FIrst Image:
Problems with this image: the URL isn't active, and redirects to TheGet.io, which looks like a pretty typical web development / marketing organization's home. Nothing like the service described in the picture is offered there.
Assuming someone did at one time offer an email system hosted in Russia, so what? There is zero / nothing to connect it to anyone in the GOP (except that the wayback machine has another URL with pictures of some famous Republicans).
The supposed email service site (NSAmail.com)) is also a dead site. Maybe someone thought this was a good idea, but like a lot of internet ventures it didn't work out as planned and is now dead. The second image:
So, this one is a screen shot from the wayback machine, so this page was up at some point in the past, but the company is now gone. (same inactive URL as previous picture).
It's a cheezy page, not professional. Look at the "Joe the Plumber" picture for instance. There is nothing to indicate that any of the people pictured had anything to do with this company.
The GOP Tech Week looks like it was a training seminar for candidates learning how to get tech-savvy about using the web in their campaign. Their is a video archive or the training still available here: GOP Tech Week 3/15/2018. The featured presenter is a fellow named Rob Robinson. Nothing nefarious about it all. To advertise the seminar he grabbed a few famous GOP related figures and posted them on the flyer.
There is no indication any of them were involved (they certainly aren't on the video of the training), or new that their pictures were being used.
In summary this looks to be just a pure nonsense propaganda Democratic Underground (aka the Dummies) mash-up job.
It doesn't stand up to even light scruitiny, it's just designed to get the faithful all wound up with bogus claims of GOP leaders (like Joe the Plumber!) using Russian email, when in fact there is no connection between any of it. (Except possibly being abandoned money-making schemes of someone loosley associate with the web marketing team at TheGet.io).