Responsibility - with 3rd party services your are mostly employee email list outsourcing the responsibility in terms of CAN-SPAM compliance although if you try hard enough you could probably still violate it by for example providing an invalid postal address. With your own employee email list solution you are responsible for making sure you are compliant and can be sued if you don't follow the guidelines most self hosted mailing software may inform you what you trying to do may be non compliment but wont force you to follow the guidelines like most 3rd party solutions will.
For example you can mail your leads without including an employee email list opted out link and can continue to mail people that have unsubscribed from your list. If you ignorant of the guidelines and the law then this could get you in trouble. Server Type VPS - This employee email list stand for "Virtual Private Server" this gives you root access and the same degree of control as dedicate server and can have your own IP address space but your are still sharing the same server with other users so there is a limit to how far you can push it.
This is a good starting solution and can be suitable for people employee email list with mailing lists of 10,000 - 50,000 subscribers depending on the server specifications. This could cost you anywhere between $30 - $200 a month dependent on country and specification employee email list Dedicated - If your mailing larger volumes of leads or are doing time based mailing where you find that people are most responsive at a certain time on a certain day for your market then you employee email list may need to be able to process a huge amount data in a very short period of time. You will need to get your self a dedicated server.