Update 3/31/2026: High Volume Email is now Generally Available (GA). Please see High Volume Email Is Now Available in Exchange Online. For latest updates on HVE, please see this post as well as this ...
Updated Mar 31, 2026
Version 6.0
Blog Post
Hi! Is the SMTP authentication with username/password (not OAUTH) for HVE impacted by the retirement of SMTP AUTH in September 2025 or is the smtp-hve.office365.com endpoint not affected?
Thanks a lot!
Was there an answer to this? I am getting conflicting information from MS Support ticket and all the articles I am reading.
Blog posts say to use HVE and continue to use basic auth and MS Support says once basic auth is deprecated, it won't work for HVE.
Is there a definitive answer to this?
ALSO PRICING!!!! Can anyone at MS provide a pricing before September GA date?
Simone_LiebalMicrosoft
lfattinger and Chipper2225 Thank you for your patience as we were preparing our official announcement regarding Authentication. I'm happy to share that we will continue supporting Basic Authentication (username/password) until September 2028 for HVE. You can find more information in the freshly publish blog post here: High Volume Email: Continued support for Basic Authentication & other important updates
Chipper2225 Regarding pricing: I hear you! We're currently in process of finalizing pricing and will share more information soon. We are aware that this is an important factor in choosing the right solution for you, so we will share this information before HVE goes GA.
Yes also for me, that's very important to know. Please give a feedback on this Microsoft
- Simone_Liebal
bogae89 Thank you for your patience as we were preparing our official announcement regarding Authentication. I'm happy to share that we will continue supporting Basic Authentication (username/password) until September 2028 for HVE. You can find more information in the freshly publish blog post here: High Volume Email: Continued support for Basic Authentication & other important updates
Yes - please clarify this, Microsoft.
- Simone_Liebal
grkuMS Thank you for your patience as we were preparing our official announcement regarding Authentication. I'm happy to share that we will continue supporting Basic Authentication (username/password) until September 2028 for HVE. You can find more information in the freshly publish blog post here: High Volume Email: Continued support for Basic Authentication & other important updates
