So I am promoting a series of business events which are basically lead generation shindigs with a sweet backend. For one of the events I was given an old, cold list from a prior company long disbanded. The list had been collected via a telemarketing campaign by the old company and everyone on it had opted in so-to-speak, the only problem was they had opted in to a totally different business entity & it was maybe 5-6 years old. They were not necessarily getting spammed (if you take my point of view) however I knew that if I ran them through an email delivery service as they were, the unsubs and spam reports as well as the bounces from long dead email addresses would sink any efforts to gain traction. To check the emails, clean the list and at the same time begin exposure them to the new brand, I used two methods involving LinkedIn & Eventbrite. What I Did. 1. I imported a CSV file of the leads into a throwaway Gmail account and added them as contacts. 2. In the LinkedIn account of the event organizer, I imported the contacts from the throwaway Gmail account. (Out of 3500 emails that it imported, it showed 840 of them were on LinkedIn) 3. Requested connection to the 840 people; 45 confirmed that day, a further 60 in the week since with more confirming every day, trickling in. (Remember, LinkedIn sends CONSTANT email reminders about requests pending. Make sure your profile pic looks good as this is displayed in the email) 4. I then set-up an Eventbrite account, set-up an event and then invited the contacts from the same Gmail account. (Eventbrite will only send out invites 2000 at a time.So do them in batches. If yours is an online business then organize an online event) 5. Eventbrite provided me with a full report on the emails sent, the bounces, the unsubscribes and the complaints. I then exported good emails as CSV. The only penalty I got was they now limited me to 500 invites at a time for this event. Eventbrite cleaned the list up just fine, exposed a few people to a free event with amazing giveaways and free business tools. 6. Next I signed up to Email delivery service, imported the cleaned list and segmented them, put together a killer free offer tied to the event and started my email campaign. So far I've sent out 2 emails, 1 complaint out of 3097 emails sent (I put unsubscribe at top of email so that may have something to do with low complaints) 1 -2.5% unsubscribe rate, 26-50% open rate (1 crap Subject line = 26% open rate. 50% open rate was a smaller list with prior exposure to Freebies). I'm pretty happy considering the nature of the list. Just have to build a relationship with them & ladden them with high value freebies and info. The main point of the exercise was to check for invalid emails, clean the list and expose a cold but targeted list to a new brand. I used both LinkedIn and Eventbrite to accomplish just that.