This excerpt taken from the EVOL 8-K filed Oct 15, 2009.
Notice. Notice will be sent, if to you, at your address as shown below; and if to Evolving Systems, at Evolving Systems headquarters location, attn: Thad Dupper, President & CEO. Notice is effective when received by the person to whom Notice is required to be given, if sent by any means that leaves a permanent record in the recipients hands. Notice is also effective if properly addressed and sent postage prepaid by any method resulting in a return receipt from the courier. Notice sent by this method is effective on the earlier of the date actually received, or on the date the return receipt shows it was refused or returned undeliverable. Either party may change its Notice address, by Notice.
6 Polo Club Drive
Denver, CO 80209
These excerpts taken from the EVOL 8-K filed Feb 27, 2008.