We do both, as needed. In this instance, I sent a detailed email this morning. He sent a detailed response in the afternoon, with an invitation to ping him to c

We do both, as needed. In this instance, I sent a detailed email this morning. He sent a detailed response in the afternoon, with an invitation to ping him to chat further about one of the topics. A few hours later, I did, and five minutes after that, he called. The emails did the job of all of the background information - facts and basic interpretation, explanation of the problem and our options. The phone call was to agree on how we should proceed.