The connection is rather obvious. The Wraith are nearly immortal and suck the life out of humans. Of course there are also differences from classical vampire lore.
The following two articles connect the Wraith to vampires:
- Wraith Be Dead? which appears to have been written very close to the premiere of SGA
- vampires.wikia.com which describes the Wraith as "race of Psi-vampires that can give and take life force by pressing their hand against someone's chest, causing them to age"
The supposed history is that the Wraith defeated the Lanteans (Ancients) 10,000 years ago via siege and overwhelming numbers, and that some of the Ancients ascended and others fled back to Earth. So the premise is there that the mythology of vampires could have originated in Wraith legend. This also agrees with Stargate's m.o. that mythology on Earth originates in real aliens or vice versa.
So now the question: Aside from everything cited above, is there direct evidence in the scripts or in statements by producers or writers that they either were inspired by or intended the Wraith to be related to Earth vampire mythology?