Nelo our VPS servers do not have e-mail limit on them here at Thexyz Server. Do note though that the sending of too many e-mails in short period of time may be the reason for the blacklisting of the VPS by spam preventing companies like CBL, Spamhause .etc. In this case due to the VPS terms of Service and the contract we have with our datacenter we will be forced to suspend the VPS.
Due to this fact the decision on the matter is up to you as you will know best how many mails is the site sending, are they send to subscribe recipients, or not and what is the chance for some of the recipients to report the e-mails as spam to the spam preventing companies.