Updates and downloads

mesu.apple.com

mesu.apple.com is an Apple host for software update catalogs. Apple lists it for iOS, iPadOS, tvOS, watchOS, macOS and visionOS.

Run by ApplePorts: 443 and 80 TCPChecked: 1 November 2026

Short answer

Apple's host for software update catalogs, the lists of updates that devices check against.

Don’t block

Don't block it. Devices can't read Apple's software update catalogs, so they may not find updates.

Matches
mesu.apple.com

A name with *. covers every name under it: *.push.apple.com matches 1-courier.push.apple.com.

What it serves

Apple's enterprise host list names mesu.apple.com in its Software updates section. Its description is “Hosts software update catalogs”.

Catalogs list what is available. The updates themselves come from other hosts in the same section, such as swcdn.apple.com and updates.cdn-apple.com.

From this Mac on 1 November 2026, mesu.apple.com resolved through a CNAME chain to a name under aaplimg.com and an address in 17.0.0.0/8. See *.aaplimg.com.

Processes that use it

softwareupdatedPart of macOS. It checks for and downloads macOS updates, security responses and system files.Process →

What breaks if you block it

Don’t block

Don't block it. Devices can't read Apple's software update catalogs, so they may not find updates.

What breaks if you block it

  • Software Update may not find available updates.
  • Security responses and other update content listed in the catalogs may not install.

With Kilobat Pro and the network filter, you can block a host for every app or for one app: in Connections, select a connection and choose Block. Apple’s own services are never blocked by Kilobat’s Protection lists.

Notes

To stop macOS updates downloading on a hotspot, turn off automatic downloads in Software Update instead. See Stop Software Update downloading on a hotspot.

Apple’s rules for its hosts

Apple’s list, Use Apple products on enterprise networks, says that devices open these connections, not Apple’s servers. Apple services fail any connection that uses HTTPS interception, so a proxy that inspects TLS should leave Apple’s hosts alone.

If a firewall allows hosts by name, allowing *.apple.com covers most Apple services, Apple says. A firewall that works only with addresses can allow 17.0.0.0/8 for IPv4, and 2403:300::/32, 2620:149::/32 and 2a01:b740::/32 for IPv6.

To see which app on your Mac opened a connection to this host, use Kilobat’s Connections tab, or the agent network log for AI agents.

Sources

Checked on 1 November 2026.