Missing e-mail notifications from gerrit about review requests

Hi, it seems gerrit doesn't send e-mail notifications to reviewers when they are added as reviewers to patches. For example, I haven't received an e-mail notification about being added as a reviewer to https://gerrit.ovirt.org/106310 and https://gerrit.ovirt.org/106311 today. I have heard from Tomasz that he has this problem for a couple of last days (at least since Friday) too. Other e-mail notifications from gerrit seem to come normally. Could you please check what's wrong? Thanks, Milan