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Online mental health communities (OMHCs) are prominent resources for improving people's mental wellbeing. An immediate cue of such improvement is support-seekers' satisfaction expressed in their replies to the received comments. However, the comments that seekers find satisfying may change with their community knowledge, e.g., measured by tenure and posting experience in that community. In this paper, we first model the amount of satisfaction conveyed in the support-seekers' replies to the received comments. Then we quantitatively examine how seekers' expressed satisfaction is affected by their community knowledge, sought and received support in an OMHC. Results show that support-seekers with more posting experience generally display less contentment to the received comments. Compared to newcomers, higher tenured members express less satisfaction when receiving informational support. We also found that support matching positively predicts seekers' satisfaction regardless of their community knowledge. Our findings have implications for OMHCs to satisfy support-seekers through their community knowledge. CCS CONCEPTS• Human-centered computing → Empirical studies in collaborative and social computing.