(Ruby) How to Download Messages in MessageSet One at a Time

If a message set contains a huge number of emails, it's NOT a good idea to try to download all at once into an email bundle using a method such as FetchBundle. It's better to iterate over the messages in the set to download one by one.

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

imap = Chilkat::CkImap.new()

# Connect using TLS.
imap.put_Ssl(true)
imap.put_Port(993)
success = imap.Connect("imap.example.com")
if (success != true)
    print imap.lastErrorText() + "\n";
    exit
end

# Authenticate
success = imap.Login("email_account_login","email_account_password")
if (success != true)
    print imap.lastErrorText() + "\n";
    exit
end

# Select an IMAP mailbox
success = imap.SelectMailbox("Inbox")
if (success != true)
    print imap.lastErrorText() + "\n";
    exit
end

# Search for messages and return a set of matching messages.
# (This example will simply search for ALL messages.)
fetchUids = true
# messageSet is a CkMessageSet
messageSet = imap.Search("ALL",fetchUids)
if (imap.get_LastMethodSuccess() != true)
    print imap.lastErrorText() + "\n";
    exit
end

print "Number of messages = " + messageSet.get_Count().to_s() + "\n";

i = 0
while i < messageSet.get_Count()
    # email is a CkEmail
    email = imap.FetchSingle(messageSet.GetId(i),fetchUids)
    if (imap.get_LastMethodSuccess() != true)
        print imap.lastErrorText() + "\n";

        exit
    end

    print email.ck_from() + "; " + email.subject() + "\n";

    i = i + 1
end

print "OK" + "\n";