keep in mind DOL rules re electronic communication; spds must be provided; certificates of coverage/booklets provided by ins co frequently don't satisfy the technical requirement so of an spd. The DOL regs require that the spd must be distributed in a manner reasonably calculated to ensure receipt of the spd and must be sent by a method likely to result in full distribution. In the past, it was mail or distributed at work; then came technology and of course, the DOL has rules for that!
The issue that everyone is concerned with is how can you prove that your participants received the spd; it is an ERISA requirement, a fiduciary responsibility. Practically speaking, where a plan sponsor is most likely to get burnt is in law suits; you see it more on the H&W side than on the retirement side. Here’s an example
http://benefitslink.com/articles/guests/washbull080616a.html