Why am I seeing iCloud email timeout errors?
Summary
What email marketers say11Marketer opinions
Marketer from Email Geeks confirms experiencing the same iCloud timeouts starting on February 7 and still persisting.
Email marketer from EmailOnAcid Forum shares that iCloud timeouts might stem from poor sender reputation. They recommend monitoring your sender score and taking steps to improve it, such as cleaning your email list and engaging with recipients.
Email marketer from Hubspot answers that you should be using double opt-in when collecting email addresses, as this is a clear indication that this user wants to recieve your email messages. This should reduce the liklihood of timeouts.
Email marketer from Litmus says that issues can come from not warming your ip addresses. They encourage senders to slowly warm up new ip addresses on different lists before sending bulk emails.
Email marketer from Stack Overflow explains that iCloud timeout errors can be caused by exceeding sending limits. He recommends throttling email sending to stay within iCloud's limits. He also suggests checking the size of attachments, as large files may cause timeouts.
Email marketer from Reddit suggests that iCloud email timeout errors can occur due to strict spam filtering. They recommend ensuring your sending domain is properly authenticated with SPF, DKIM, and DMARC records.
Email marketer from Quora suggests that iCloud email timeout errors can arise from blacklisting. Check if your IP or domain is on any major email blacklists and take steps to be removed if listed.
Marketer from Email Geeks shares that they also experienced iCloud timeout errors and contacted iCloud's team, who responded that they had investigated the report and made appropriate changes. They were asked to resend and report if the issue persists.
Email marketer from Mailjet support shares that large email sizes can cause timeouts. They advise compressing images and reducing the overall email size to improve sending reliability.
Marketer from Email Geeks says that they are also running into iCloud timeout errors with no discernible pattern, despite most emails to private relay addresses being sent without issue. The issue has been ongoing for about a week.
Email marketer from Sendgrid answers that rate limiting your email sends is important, as high volumes of email sent too quickly will likely be affected by rate limiting.
What the experts say3Expert opinions
Expert from Word to the Wise explains that greylisting (temporary rejection) by the receiving server, often used by iCloud, can cause apparent timeout errors if retries are not handled properly by the sending server. They suggest ensuring your sending server correctly implements retry mechanisms as per SMTP standards.
Expert from Email Geeks shares that timeout errors with iCloud often occur when their infrastructure is overwhelmed, suggesting that ESPs can easily exceed their capacity.
Expert from Spam Resource shares that incorrect network configurations, particularly related to Maximum Transmission Unit (MTU) size, can result in timeout errors. They advise checking and adjusting MTU settings on your server to ensure they are compatible with iCloud's network requirements.
What the documentation says5Technical articles
Documentation from MXToolbox suggests that timeout errors can indicate DNS resolution problems. They advise using their DNS lookup tools to verify that your domain's DNS records are correctly configured and resolving properly.
Documentation from Apple Support explains that iCloud Mail might experience temporary server issues, causing timeouts. They recommend checking the Apple System Status page for any reported outages or maintenance. If there are no reported issues, they suggest trying again later.
Documentation from AWS SES says that timeout issues are usually caused by network problems, and encourages checking the amount of hops an email takes to check for long delays, and also to retry the message later.
Documentation from Microsoft says that NDR errors can be caused by mail loop issues. They suggest checking your forwarding rules and mail configurations for configuration errors, to stop these looping messages being sent over and over.
Documentation from RFC 5321 (Simple Mail Transfer Protocol) explains that SMTP timeout errors occur when a server doesn't receive a response from another server within a specified time. It suggests that network congestion or server overload can cause these timeouts.