charley9broth. - I know that this problem has a solution. Similarly, it is important to know which provider you use. I used to have Thunderbird and my ISP was always blocking my messages to subscribers. Then I discovered this site https://www.outlooktransfer.com/ and I found out that there is a utility that you can download for free that will help you with outlook migration tool. Because I like this commercial better.

vasilbegdov - Who has worked with Microsoft Graph? Can you explain how to work with their API to use it in your tasks to get data from Office 365?

vasilbegdov - How to work with the API? To receive and transmit all data, as well as to be able to transfer the same data between several computers.

raniwe - Working with graphs is very difficult, especially when you have not used such APIs before. I figured everything out myself only after I read an article about microsoft graph explorer https://www.starwindsoftware.com/blog/getting-started-with-microsoft-graph-explorer and how to work with it. Difficulties will be at the stage of receiving errors from use, so carefully read the documentation on the Microsoft website. It will describe the errors and how to fix them.

milania - You need to test until you are sure of the quality of the product. I think it doesn't matter if it's your team, or a remote one, the main thing is that due attention is paid to this. I advise you to read this information https://solidbrain.net/blog/automated-vs-manual-testing in order to choose the right testing method.

tomas7 - Thank you for your advice, but I would also like to know about how I can make my own application faster and less expensive? Any ideas?