What is everyone using these days?
Well to be honest, it's usually one of the below depending how often you need to email your DJ promo list and whether or not you are doing your own distribution.
FatDrop

Fatdrop accounts costs £50 with a monthly fee starting at £35/month.
Label Worx

Label Worx charge £7.50 / promo campaign.
Label Engine

Pricing for the promotional system starts from $23.99 / month.
Inflyte

Pricing starts at £40/month.