sed problems - Bash Script

Hi
I keep getting the following error

sed: -e expression #1, char 32: unterminated `s' command
sed: -e expression #1, char 35: unterminated `s' command
sed: -e expression #1, char 35: unterminated `s' command

whenever I use the following bash script

#! /bin/bash
mailgmail="smtp\.gmail\.com:587"
mailyahoo="smtp\.mail\.yahoo\.com:587"
echo "Email:"
        read emailuse
echo "Password:"
        read emailpass
sed -i "6s/.*/root=$emailuse/" /etc/ssmtp/ssmtp.conf
sed -i "25s/.*/AuthUser=$emailuse/" /etc/ssmtp/ssmtp.conf
sed -i "26s/.*/AuthPass=$emailpass/" /etc/ssmtp/ssmtp.conf
if [[ "$emailuse" == *"gmail"* ]]; then
        sed -i "10s/.*/mail=$mailgmail" /etc/ssmtp/ssmtp.conf
        sed -i "23s/.*/mailhub=$mailgmail" /etc/ssmtp/ssmtp.conf
        sed -i "28s/.*/mailhub=$mailgmail" /etc/ssmtp/ssmtp.conf
elif [[ "$emailuse" == *"yahoo"* ]]; then
        sed -i "10s/.*/mail=$mailyahoo" /etc/ssmtp/ssmtp.conf
        sed -i "23s/.*/mailhub=$mailyahoo" /etc/ssmtp/ssmtp.conf
        sed -i "28s/.*/mailhub=$mailyahoo" /etc/ssmtp/ssmtp.conf
else
        echo "Use another email address with yahoo or gmail"

fi

Thank you

Reading the error messages carefully: try terminating each of those sed s ubstitute commands with a slash...

The closing / are missing. For example

    sed -i "
      10s/.*/mail=$mailgmail/
      23s/.*/mailhub=$mailgmail/
      28s/.*/mailhub=$mailgmail/
    " /etc/ssmtp/ssmtp.conf

Multi-statement per one sed is more efficient.