Ten-man Southend picked up their second successive goalless draw at Roots Hall as Dagenham slipped into the League Two relegation zone.
The visitors looked to have taken the lead when Shrimpers defender John White put the ball into his own net, but it was disallowed for offside.
Southend then went close through Jack Payne and Barry Corr, before the Daggers’ saw a second shot ruled out.
Cian Bolger then saw red for violent conduct with 20 minutes remaining.
The Irishman was penalised for a foul on visiting goalkeeper Mark Cousins, before referee Gavin Ward brandished a straight red card to Bolger for an incident involving Joss Labadie.
Phil Brown’s side have now not conceded at home in League Two for 379 minutes, while Dagenham fall to 23rd after Tranmere’s victory at home to Northampton.