Introduction
Sometimes emails sent from University of Pittsburgh addresses may be delayed or not delivered because our email servers have been added to an email "blocklist" (also called a "denylist"). This is a common challenge that affects universities and organizations worldwide.
A blocklist is a database of email servers that have been reported for sending unwanted bulk emails (spam). Many email providers use these lists to protect their users by blocking or delaying messages from servers on these lists.
The main cause of blocklisting at universities: When people forward their university email to personal accounts (like Gmail or Yahoo) without proper spam filtering, spam messages get forwarded too. The external email service then incorrectly identifies the university as the source of spam and blocks future emails from our servers.
The good news: Spam filtering is automatically enabled for all University email accounts, which helps prevent this issue.
Information
What is an email blocklist?
An email blocklist (previously called a "blacklist") is a list maintained by anti-spam organizations that tracks email servers suspected of sending spam. Email administrators can configure their systems to automatically reject or delay messages from any server on these lists. This helps reduce the amount of spam that reaches their users' inboxes.
Why might Pitt's email servers end up on a blocklist?
The University allows students, faculty, and staff to automatically forward their Pitt email to personal email accounts (such as Gmail, Yahoo, Outlook.com, or others). When spam filtering isn't enabled for these forwarding settings, spam messages that arrive at your Pitt account also get forwarded to your personal account.
Here's the problem: Because these messages are being forwarded through University servers, email providers like Google or Yahoo see the University as the sender. If they receive enough forwarded spam, they may add our servers to their blocklist, assuming we're the source of the spam rather than just forwarding it.
How does blocklisting affect email delivery?
If you send an email from your Pitt account to someone whose email provider is currently blocking our servers, your message will bounce back undelivered. This only happens when our servers are actively blocklisted, which may last anywhere from a few hours to several days, depending on the situation.
What Pitt is Doing
Technical protections in place
Pitt's Digital continuously monitors email delivery and works to prevent blocklisting through several measures:
- Automatic spam filtering: All University email accounts have spam filtering enabled by default, especially for accounts that forward to external addresses
- Active monitoring: We track our server reputation across major email providers
- Authentication protocols: We use modern email authentication standards (SPF, DKIM, and DMARC) to verify that emails from Pitt are legitimate
- Rapid response: When blocklisting occurs, we work to resolve the issue and request removal from blocklists
Why removal can be challenging
Getting removed from blocklists isn't always straightforward:
- Most blocklist services are automated with limited human oversight
- Removal requests are typically handled through online forms only
- Even after removal, our servers can be re-listed if more forwarded spam is detected
- Many blocklist services don't distinguish between servers that forward spam and servers that originate spam
What You Can Do
Best practices to prevent blocklisting
Our strong recommendation: Avoid forwarding your Pitt email to personal accounts. Instead, consider these alternatives:
- Use email clients or apps: Access your Pitt email through applications like Outlook, Apple Mail, or the Gmail app (you can add your Pitt account as a separate inbox)
- Check Pitt email directly: Visit your University email through the web portal regularly
- Understand your responsibility: Your @pitt.edu address is your official university email. Even if you prefer reading email elsewhere, you're responsible for all messages sent to your University address
If your email bounces due to blocklisting
If your legitimate email is rejected and you receive a bounce-back message mentioning blocklisting:
- Contact the recipient directly through an alternative method (phone, text, or another email address)
- Explain the situation: Let them know your email was incorrectly blocked
- Ask them to report it: Request that they contact their IT support or help desk to report that legitimate email from the University is being blocked
- Try again later: Blocklist entries often expire within hours or days
Need Help?
If you have questions, experience persistent email delivery problems, or need assistance with your email settings, please contact:
Technology Help Desk
Phone: 412-624-HELP (412-624-4357)
Website: Technology Help Desk in the Service Catalog