Zoho Mail for Collaboration is so slow and cannot receive attach file?

Zoho Mail for Collaboration is so slow and cannot receive attach file?

Hi Zoho Mail Support Team,

I am just setting up an domain call "insenvang.com". Everything is OK but there are some problems suddenly happen. There are:
- I send an email (from Gmail) with attach file - the size is less than 20 MB - to an email like <user>@insenvang.com, I'm waiting but cannot receive anything.
- A file size is less than 1 MB, under Outlook 2013, it takes about 5 minutes to download, at last, it fails too. The program still cannot download the file.



Please help me to tweak Zoho Mail working smoothly with Outlook 2013!!!

Thanks for your consideration.
Học Nguyễn Triết.