Comment # 1 on bug 1048109 from Andreas Stieger

(In reply to Sebastian Siebert from comment #0)
> I see that the package "php5-imap" for PHP 5 is missing for Tumbleweed or in
> the PHP repo. For PHP 7 the package is available.

Dropped intentionally. From https://build.opensuse.org/request/show/505809:
"Drop imap support, it depends on obsolete imap package"

> It has to be secured that the package should be available for the next
> openSUSE release 42.3.

There is no change for openSUSE:Leap:42.3/php5, it will continue to ship the
php5 source from SLE 12, not Factory. 

php5-imap is and will be available in 42.3. Closing as invalid.