client communication includes any verbal or written communication addressed to a specific person or household as opposed to Public Communication which is addressed separately [here]

synchronous communication:

The very best way to build relationships, avoid misunderstanding, and engage in meaningful connection is through a synchronized conversation. This is how business should be conducted and can be in person, phone call, or video conference.

We can easily document these interactions in our [CRM]

It’s always our preferred method of communication.

email:

great for setting up meeting times, gathering some generic information, sending file upload links, sending updates and newsletters

we can use email for pretty much anything other than:

• account numbers
• statements
• personal and sensitive information
• social security numbers
• trading instructions or cash requests

We keep our systems as secure as possible, but email is a two-way street, there's no way of knowing whether or not your client's account could have been compromised.

Let's assume email is public record, be careful with personal information.