Slate says mmmmprobably.
Mother Jones says ZZOMFGOFCOURSE!!!!One
NYT says blahblahblahblahprollynot
- In classified sessions in August and September, intelligence officials also briefed congressional leaders on the possibility of financial ties between Russians and people connected to Mr. Trump. They focused particular attention on what cyberexperts said appeared to be a mysterious computer back channel between the Trump Organization and the Alfa Bank, which is one of Russia’s biggest banks and whose owners have longstanding ties to Mr. Putin.
F.B.I. officials spent weeks examining computer data showing an odd stream of activity to a Trump Organization server and Alfa Bank. Computer logs obtained by The New York Times show that two servers at Alfa Bank sent more than 2,700 “look-up” messages — a first step for one system’s computers to talk to another — to a Trump-connected server beginning in the spring. But the F.B.I. ultimately concluded that there could be an innocuous explanation, like a marketing email or spam, for the computer contacts.
/u/LeavesTeaLeaves http://gdd.i2p.xyz/ https://krypt3ia.wordpress.com/2016/10/08/gdd53-a-russian-hosted-i2p-site-that-claims-trumps-email-system-had-ties-to-alfabank-russia/ I have no idea if this means anything but... there it is... apparently from the horse's mouth.
(rehosted image:) 
Well Paul Vixie (the dude who wrote DNS) says that this is pretty clearly person-to-person communication, and not an automated thing like spam or email. “The data has got the right kind of fuzz growing on it,” Vixie told me. “It’s the interpacket gap, the spacing between the conversations, the total volume. If you look at those time stamps, they are not simulated. This bears every indication that it was collected from a live link.” I asked him if there was a chance that he was wrong about their authenticity. “This passes the reasonable person test,” he told me. “No reasonable person would come to the conclusion other than the one I’ve come to.” Others were equally emphatic. “It would be really, really hard to fake these,” Davis said. According to Camp, “When the technical community examined the data, the conclusion was pretty obvious.”
Rob Graham says no--it looks like a standard mail server run by a marketing company: http://blog.erratasec.com/2016/11/debunking-trumps-secret-server.html
Yeah, there's no reason to believe this claim: https://theintercept.com/2016/11/01/heres-the-problem-with-the-story-connecting-russia-to-donald-trumps-email-server/