Hi @Imdad Ali ,
do we support TLS 1.3 in Microsoft SMTP Server
If by Microsoft SMTP Server you mean "Exchange Online", no, currently there's no information or official announcement about the supportability of TLS 1.3.
If you are talking about on-premises Exchange like Exchange 2019, it's not yet supported either at this time. Below are some links for reference:
- Exchange Server Roadmap Update - Support for TLS 1.3
- TLS 1.3 support on Exchange Server 2019(WIN2k22)
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