SoapFault exception: [HTTP] Could not connect to host / php imap - signature has expired

Question

If anyone is having issues with these errors, theres been compatibility changes to LetsEncrypt. Unless both your polling and answering server are on compattible versions, you can fix your error by ensuring that your openssl version is < than the following

    OpenSSL <= 1.0.2
    Windows < XP SP3
    macOS < 10.12.1
    iOS < 10 (iPhone 5 is the lowest model that can get to iOS 10)
    Android < 7.1.1 (but >= 2.3.6 will work if served ISRG Root X1 cross-sign)
    Mozilla Firefox < 50
    Ubuntu < 16.04
    Debian < 8
    Java 8 < 8u141
    Java 7 < 7u151
    NSS < 3.26
    Amazon FireOS (Silk Browser)

these are the affected clients that will still trust the exiting certificate chain

also, as reference,

https://community.letsencrypt.org/t/help-thread-for-dst-root-ca-x3-expiration-september-2021/149190/264

Answer 1

as described above, and refer to https://community.letsencrypt.org/t/help-thread-for-dst-root-ca-x3-expiration-september-2021/149190/264