Two headers from Barry Corr saw the Shrimpers fight back from 2-0 down to claim a 2-2 draw with Uwe Rosler's side at Roots Hall on Saturday.
Meanwhile, Chelsea eased past Premier League rivals Southampton 5-1 at St Mary's.
The fourth round tie will be played over the weekend of January 26/27.
- Sports & Recreation
- Barry Corr
- Uwe Rosler