When you talk with someone face to face, you can see things which confirm or detract from wishing to pursue a relationship. True in business, work or social settings. You see some things, you feel others.
When you communicate with someone by email for the first time, these signals are rarely conveyed but when they are they are often weak and inconclusive
If an in-person meeting is not appropriate, you can increase the weak “signal strength” with a phone call.
Next step is a video call.
If in any doubt – you really should!