Synder - AR Automation

Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues

Codat - Codat works with lenders, banks, insurers and software providers to provide integrations with the accounting and other financial softwares.

mlist - Email newsletters, outside of the inbox

Railz - Build Financial SME apps using normalized Accounting data

TL;DR Email - Send short emails & read emails as fast as you read Facebook