I was contacted by a company who said we create you a perfect email marketing campaign and send it out to 10,000+ clients...
Anyone on this forum offer this and can shed some light on this please?”
Its rubbish ignore it.
Data is the currency of the digital world we live in. But data has a huge flaw, it degrades. If you have a database of say 1000 previous clients, that information is only as good as the last time you spoke to them. If that data is 6 months old, some clients will be no more, ceased trading, moved address, changed contact details, or have opted out of marketing, such as TPS or MPS.
If that data is 2, 5, 10 years+ old, it will be mostly worthless, and legally unusable.
Now if I offer you a targeted list of 10,000 potential leads, with current up to contact details, with opted in permission to be contacted (that hasn't been sent to death), how much do you think that would cost? You can get this data, you can buy it in directly from companies house and other providers and it is very expensive.
Professional data houses will normally give you some sample data to evaluate and test, plus they would never use a web email address, it would be come from their own domain.
Selling data is a huge business, and old data lists are regularly nicked, scraped, repackaged and sold, again and again and again. If you get lots of business type spam, then your email is on one of them. Unfortunately until people stop buying this rubbish, it will never end
Using old/dirty data will at best leave you out of pocket, and worst land you in serious trouble as well as causing brand reputation damage.