We compared 20 international popular email providers considering performance, practicability and transparency as main criteria to find out which providers work well with Delta Chat. We published a table with the measurement results in our blog: Which e-mail providers work well with Delta Chat? Quite some :) - Delta Chat
In the table you will see both qualitative and quantitative evaluations. We measured things like message sending speed, attachment size, steps for the set up with Delta Chat, IMAP features and more. Please let us know what you think about it!