constant contact / mail monkey type emailers ? UK

I have a list of maybe 40k , mainly UK emails thats needs to be screened for hard & soft bounces , and hot a few times for opt outs etc ..Im kinda guessing after cleaning a few times it will be les than 10k active if not 5k.... I have been looking at a quality emil compnay such as constant contact and mail monkey type emailers but certainly for the initial first few hits for cleaning i feel they are too expensive

ANybody any experience of other cheaper companies , ideally ones with reputation tht they dont reuse your email addresses etc

any help apprecited

 

Stil on the hunt for a decent company if anyone has any ideas

 

I use campaign monitor a lot. Good company, but not much cheaper than CC.