Problem with conveyancing digital system

I am a conveyancer using the e4 conveyancing program. Generally I am satisfied with the service I get, but since about a month ago I encountered a problem with their program which they seem not being able to solve. On the conveyancing program e4 has an e-mail service through which the conveyancer reports progress with property transfers to buyers, sellers and estate agents on a regular basis. Suddenly the e-mails that I send do not reach their destination. I reported this problem to e4 and they requested me to update my SPF records by doing a "whitelisting" on my system. As this is not within my knowledge to do this, I asked my WiFi service provider (MWeb) to do it, but they referred me back to e4. e4 tried to help me but in the end they insisted that I must get an IT person to do the "whitelisting". I discussed it with an IT specialist and he is adamant that the "whitelisting" must be done on the e4 server by e4 themselves. As this problem has remained unresolved for a month now, I am very frustrated and in desperate need of a solution to this problem.