One email take minute to download

I have 105 MBPS download connection. I have this app on my iPhone 7plus. I will get a notification saying that I have an email with few email lines. Then when I click on that notification, this app will literally takes minute to download an email which is about 15 Kbps. So for a minute I am sitting with a totally blank content email.

When I am sending the email, it take minute to send and to hear the sent sound. My iPhone 6 does not have this issue.

I only have one live account in this app and it is doing that to the live account.

I do not know why it would do this.

Other than that. I really like this app. I hope the developer fixes it fast before I switch to something else.

FlyingSoldier about Email - Edison Mail, v1.4.3