To be honest, email lists are usually garbage. If you are sourcing prospects, use a well-known database like Apollo.io and be specific on your targeting criteria that fits your ICP. There is an Alchemist company (LeadIQ) that also does similar but via LinkedIn. Their approach is to do targeted sourcing via LinkedIn and do real-time lookup of people's information. There is an Alchemist discount of 50% for 6 months for basic plan.
If you have a targeted tradeshow that you think the list would be beneficial, try VisitorsList for email list. Prices are very reasonable.