Hi HusseinAkberali,
You can connect up to five other accounts, such as Hotmail, Gmail, and Yahoo! Mail accounts. This lets you send, receive, and read email all in one place.
To create a connection to another account, please refer to the following steps below:
1. Before you connect to download mail from another email account, you may need to turn on POP or IMAP access from the other account. For more information, see Turn on POP or IMAP access to connect to another account.
2. In Outlook Web App, click Settings
> Options> Account> Connected accounts.
3. Click New 
.
4. In the New Account Connection dialog box, type the email address and password of the account you want to connect to, and then click Next.
5. When you see the message that your accounts are connected, click Finish. Messages sent to your connected account will appear in your Inbox.
For more information:Connected accounts
Moreover, you can use your Windows Phone devices, to share a document or folder in a library with people outside your organization. You do this either by inviting people to join your site or by sharing a guest link. To do this, please refer to the article Share documents by using a mobile device
If you have any question about your issues and solutions. Please don’t hesitate to contact us.
Best regards,
Shyamal