Summary
Office365 temporary failures (temp fails) arise from a multitude of factors related to service health, email infrastructure, and sender reputation. Key causes include Microsoft service outages, network congestion, Exchange Online Protection throttling, greylisting, poor sender reputation stemming from spam complaints or sending to invalid addresses, blacklisting, inadequate email authentication (SPF, DKIM, DMARC), exceeding sending limits, using new or unwarmed IP addresses, and maintaining poor email list hygiene. Resolution strategies involve retrying email delivery, checking Microsoft's service health dashboard, investigating sender reputation via tools like Google Postmaster Tools, ensuring valid rDNS records, adjusting sending volumes, gradually warming up new IPs, cleaning email lists, properly configuring email authentication protocols, checking blacklist status and taking steps to delist, and investigating the recipient's setup if it's an isolated issue. If it is a widespread issue it could be a problem on the Microsoft side.
Key findings
- Microsoft Infrastructure: Microsoft service outages, network congestion, and Exchange Online Protection throttling can all cause temp fails.
- Sender Reputation: Poor sender reputation, stemming from spam complaints, sending to invalid addresses, or blacklisting, significantly contributes to temp fails.
- Authentication: Lack of proper email authentication (SPF, DKIM, DMARC) increases the chances of temp fails.
- Sending Practices: Exceeding sending limits, using new or unwarmed IPs, and poor list hygiene lead to deliverability issues and temp fails.
- Greylisting: Greylisting, an anti-spam technique, can cause initial temporary failures requiring retries.
- rDNS: Missing or invalid rDNS records can cause deliverability problems.
Key considerations
- Check Microsoft Health: Regularly check the Microsoft service health dashboard for reported outages.
- Monitor Reputation: Actively monitor sender reputation using tools like Google Postmaster Tools.
- Implement Authentication: Ensure proper configuration of SPF, DKIM, and DMARC.
- Manage Sending Volume: Adhere to Office365 sending limits and gradually warm-up new IP addresses.
- Maintain List Hygiene: Regularly clean email lists to remove invalid and unengaged addresses.
- Check Blacklists: Monitor and address any blacklist listings promptly.
- Review Configuration: If a problem occurs for a single recipient look at their configuration.
What email marketers say
7 marketer opinions
Office365 temporary failures (temp fails) can stem from various issues impacting email deliverability. These include being blacklisted, experiencing reputation problems, lacking proper email authentication (SPF, DKIM, DMARC), exceeding sending limits, sending from new or unwarmed IP addresses, and maintaining poor list hygiene. Resolution involves checking blacklist status, monitoring sender reputation via tools like Google Postmaster Tools, ensuring valid rDNS records, adjusting sending volume, gradually warming up new IPs, cleaning email lists, and correctly configuring email authentication.
Key opinions
- Blacklisting: IP address or domain being listed on real-time blacklists (RBLs) causes temporary failures.
- Reputation Issues: Poor sender reputation negatively impacts deliverability, leading to temp fails.
- Authentication: Lack of proper email authentication (SPF, DKIM, DMARC) increases the likelihood of temporary failures.
- Sending Limits: Exceeding Office365's sending limits can result in temporary failures.
- IP Warm-up: Sending from new or unwarmed IP addresses can cause deliverability issues.
- List Hygiene: Poor email list hygiene (sending to invalid or unengaged addresses) negatively impacts sender reputation and deliverability.
Key considerations
- Check Blacklists: Regularly check your IP address and domain against RBLs to ensure you are not listed.
- Monitor Reputation: Use tools like Google Postmaster Tools to monitor your sender reputation and identify potential issues.
- Implement Authentication: Correctly configure SPF, DKIM, and DMARC to authenticate your emails and improve deliverability.
- Respect Sending Limits: Adhere to Office365's sending limits to avoid being throttled or blocked.
- Warm-up IPs: Gradually warm up new IP addresses to establish a positive sending reputation.
- Clean Lists: Regularly clean your email lists to remove invalid and unengaged addresses.
- rDNS Records: Ensure the sending infrastructure has a valid reverse DNS (rDNS) record.
Marketer view
Email marketer from SocketLabs stresses the importance of maintaining clean and engaged email lists. Sending to invalid or unengaged email addresses can negatively impact sender reputation, contributing to temporary failures. Regularly cleaning your lists helps improve deliverability.
31 Dec 2021 - SocketLabs
Marketer view
Email marketer from Reddit explains that temp fails may be resolved by ensuring your sending infrastructure has a valid reverse DNS (rDNS) record, checking your IP address's reputation, and making sure your sending volume is consistent.
6 Feb 2023 - Reddit
What the experts say
5 expert opinions
Office365 temporary failures (temp fails) can be attributed to various factors. While a 'server busy' message isn't typically a block, throttling by Exchange Online Protection is a potential cause, especially if the message specifies the sending IP. Occasional Microsoft outages can also trigger these failures. Additionally, greylisting, an anti-spam technique involving temporary rejections, and poor sender reputation stemming from spam complaints or invalid addresses, can lead to temp fails. Investigating the recipient's specific configuration if it's an isolated incident or acknowledging potential Microsoft-side issues if widespread are also important considerations.
Key opinions
- Throttling: Exchange Online Protection throttling can cause temporary failures.
- Microsoft Outages: Microsoft outages can lead to temporary failures.
- Greylisting: Greylisting can cause temporary failures as receiving servers initially reject emails from unknown senders.
- Sender Reputation: Poor sender reputation significantly contributes to temporary failures.
Key considerations
- Investigate Isolated Issues: If the issue is isolated to one customer, examine their specific configuration and sending practices.
- Acknowledge Microsoft Issues: If multiple customers are affected, consider the possibility of a temporary Microsoft-side issue.
- Retry Delivery: Understand that greylisting requires the sending server to retry delivery for successful email acceptance.
- Monitor Reputation: Actively monitor and maintain a good sender reputation to prevent being flagged by receiving servers.
Expert view
Expert from Email Geeks shares that server busy is not usually a block in her experience.
5 Oct 2023 - Email Geeks
Expert view
Expert from Word to the Wise (Laura Atkins) explains that greylisting, a common anti-spam technique, can cause temporary failures. Receiving servers temporarily reject emails from unknown senders, requiring the sending server to retry delivery. If retries succeed, the email is accepted.
19 Dec 2024 - Word to the Wise
What the documentation says
3 technical articles
Microsoft documentation attributes Office365 temporary failures (tempfails) to service outages, network congestion, filtering problems, and exceeding Exchange Online's sending limits (throttling). Resolution strategies include retrying the email after a delay, checking the service health dashboard for outages, verifying the sender's reputation, and adjusting sending patterns to comply with sending limits. Tempfails are often indicative of transient issues.
Key findings
- Service Outages: Office365 service outages can cause temporary failures.
- Network Congestion: Network congestion can contribute to temporary failures.
- Filtering Problems: Email filtering issues can result in temporary failures.
- Throttling: Exceeding Exchange Online's sending limits leads to throttling and temporary failures.
- Transient Issues: Tempfails often indicate a transient problem.
Key considerations
- Retry Sending: Retrying the email after a delay can resolve temporary failures caused by transient issues.
- Check Service Health: Check the Office365 service health dashboard for known outages.
- Verify Sender Reputation: Verify the sender's reputation to ensure it's not contributing to deliverability issues.
- Adjust Sending Patterns: Adjust sending patterns to comply with Exchange Online's sending limits.
Technical article
Documentation from Microsoft Learn outlines troubleshooting steps for email delivery issues, mentioning that tempfails can indicate a transient problem. It suggests checking the service health dashboard for known outages and verifying the sender's reputation.
4 Jul 2024 - Microsoft Learn
Technical article
Documentation from Microsoft Learn explains that temporary failures (tempfails) can be caused by various issues, including service outages, network congestion, or filtering problems. It indicates that retrying the email after a delay is a common solution.
1 Oct 2023 - Microsoft Learn
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