Quick guidance
You generally do not need to allow-list MailChannels IPs. If a recipient explicitly insists on IP allow-listing, you must also have the SPF record below in place.

Required SPF record (must be present)

Add (or merge) this TXT record at your domain’s DNS:

We also have a guide on this here – https://kb.wpcloud.wiki/knowledge-base/setting-up-spf-records-for-mailchannels-email-authentication/

v=spf1 a mx include:relay.mailchannels.net ?all

Optional: IP ranges to share with recipients who insist on allow-listing

If a recipient’s filtering system requires fixed IPs, provide the list below.

23.83.208.0/20
46.232.183.0/24
199.10.31.235/32
199.10.31.236/32
172.255.62.10/32
54.245.125.39/32
103.18.109.138/32
54.214.232.113/32
172.255.62.11/32
185.67.193.67/32
35.85.190.185/32

Note
These IPs are provided for cases where recipients require allow-listing. For typical delivery, SPF is sufficient.