Email and voice service

We have both Broadcast by Email and also Broadcast by Voice — I understand the voice messages are using VOIP channels that we’ve purchased from Callcentric, but what path do emails sent by Voicent use? If we have a Broadcast by Email and a Broadcast by Voice running at the same time, is there any interaction between the 2 broadcasts or any impact to the speed of either broadcast from running them concurrently?

Email is sent to the defined SMTP server, which may belong to your company or your ISP. Unless you are sending email with a large attachment, it normally have less bandwidth requirement than voice calls. Besides they all use your internet bandwidth, there is no interaction between the two programs.