Looks like Microsoft is blocking our Company websites and social media.

[Andrew_Bolger]

I work for a company who email at the moment is being listed as Spam/Phish for all other companies who use O365 exchange for email. 

This all started a few days ago with no changes been made on our side. 

We noticed our website and links to our LinkedIn, Twitter and Facebook pages in our signature were being flagged as Spam by MS on our own tenant. We resolved those issues on our tenant but we are getting reports that our customers, vendor, and other 3rd parties are blocking us as well. All of which use O365 for email. 

The level1 engineer helped us unblock from our own tenant but has offered little help in terms of why it happened or can help with unblocking our company for all O365 customers. 

Even though we didn't make any changes on our side to cause this in an effort to resolve the issue have cleaned up our SPF and DMARC and have noticed we are on the UCEPROTECTL2 because our IP is bundled in with a /14 subnet that was seen spamming but our individual IP is not on the L1 or L3 blacklist. I am also unsure if this is related due to our social media pages also been seen as Spam/Phish. 

We have been calling MS regularly asking for escalations but unable to get a level2 engineer on the line. We have just repeatedly being told to wait for the engineer to call us. We keep waiting but get no call. This is frustrating as it having a major impact on our business and this has been going on for a week currently and still on-going. 

If we knew why MS is blocking us then maybe we could address it if the issue is on our side but we simply can't identify the source without MS help.

Can anyone here help? 

[#2]

@Andrew_Bolger Microsoft sends email to users on which emails it blocks now it is left to the user to decide to allow or not find the attached screenshot what i understand it blocks everyone outside the organization 

 

[#3]

If your emails are marked as spam by other vendors then I am pretty much sure your email are going via HRDP. Please share one sample message header. so We can explain you whats going on and what is the solution

[#4]

@SABBIR_RUBAYAT Attached is the screenshot of email header for us it all started from past 15-20 days initially though they are spam email but later i found they are asking for approval to allow email that are outside the organization . the attachment lists 11 email that were blocked 
Please "Accept as Answer" if it helped so it can help others in community looking for help on similar topics.