Outlook with Gmail

We are using BSNL broadband for about a decade. Recently for last 5 days our outlook stopped synchronizing with our gmail account on BSNL boroadband only. All the setting are as per recommendation and it stopped working all of a sudden since 29-09-2017. Earlier it use to work perfectly. Especially incoming mail server IMPA:993. Outgoing Server SMTP:465 seems to be working.

Can you suggest for resolution