[exim] Authentication stopped working 4.51

I've just upgraded from 4.34 to 4.51 and gone from Redhat 9 on
the server to Fedora Core 2.    For some reason authentication
has stopped working - or to be more accurate, either it has
stopped or OpenSSL encryption or PAM aren't working correctly.

My question: is the following authenticators section, which
worked fine for 4.34, still sensible?


begin authenticators

plain:
driver = plaintext
public_name = PLAIN
# Only do Auth if connection is encrypted
server_advertise_condition = ${if eq{$tls_cipher}{}{no}{yes}}
server_prompts = :
server_condition = ${if pam{$2:${sg{$3}{:}{::}}}{yes}{no}}
server_set_id = $2

login:
driver = plaintext
public_name = LOGIN
# Only do Auth if connection is encrypted
server_advertise_condition = ${if eq{$tls_cipher}{}{no}{yes}}
server_prompts = "Username:: : Password::"
server_condition = ${if pam{$1:${sg{$2}{:}{::}}}{yes}{no}}
server_set_id = $1




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It might look like I'm doing nothing,
but at the cellular level I'm really quite busy.
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