What you’re seeing
- Outbound mail from a brand-new Microsoft 365 organization bounces with code 5.7.708.
- The bounce mentions that traffic is not accepted from the sending IP or that the tenant's sending is limited.
- Internal mail between colleagues works, but customers and vendors never receive messages.
- The problem showed up within days of setting up the tenant or moving the domain over.
Common causes
Every environment is different, but these are the causes our engineers find most often:
- Microsoft routes mail from new tenants through a lower-reputation pool of servers until the tenant establishes a sending history.
- The tenant was set up with only the default onmicrosoft.com domain or before the custom domain was fully verified.
- SPF, DKIM or DMARC for the custom domain are missing or incomplete, so Microsoft treats the traffic as higher risk.
- A burst of outbound mail soon after setup looked like spam and triggered additional restrictions.
- The organization has few or no paid licenses yet, which Microsoft weighs when deciding whether to trust a new tenant.
Why it matters
A new tenant that cannot email the outside world defeats the purpose of moving to Microsoft 365. Businesses switching providers or launching a new company find they cannot reach customers during the very period they are trying to get established. Staff often fall back on personal email accounts, scattering business correspondence where it isn't backed up or protected, and the cut-over date slips while the problem is sorted out.
How AskTechGurus fixes it
Skip the trial and error. A certified engineer works on your actual system, finds the root cause, and fixes it properly.
Tell us what’s happening
Submit a ticket in about two minutes. Paste the error, describe what changed, and pick your tier. No charge to submit.
A certified engineer diagnoses it
A vetted, US-based systems engineer claims your ticket, usually within minutes during business hours, and investigates over a secure remote session you can watch and end at any time.
Fixed and verified with you
The engineer resolves the root cause and confirms with you that it’s working. You don’t just get a workaround, and you get a plain-English summary of what was wrong.
Pay only when it’s resolved
Fixed price from $99, invoiced only after you approve the fix. If it isn’t resolved, you don’t pay.
Frequently asked questions
Did we set something up wrong?
Not necessarily. Microsoft deliberately limits new tenants to fight spam. Correct domain setup and authentication help a great deal, and our engineer reviews both.
Will this go away on its own?
Sometimes, as the tenant builds a history, but there is no fixed timeline. Making sure everything Microsoft looks at is properly configured gives you the best chance of getting through quickly.